The Evolution of the Roman Imperial Fleets

D. B. Saddington


Like the ancient Israelis, who felt concern for those “who went down to the sea in ships” (Ps 107.23), the Romans, especially by comparison with the Greeks, have often been regarded as reluctant seafarers. Before the Battle of Actium Plutarch (Ant. 64) has a centurion adjure Antony, as Shakespeare puts it, not to “fight by sea; Trust not to rotten planks.” But the Romans had a port in the city and put a ship’s prow on their early coins. They developed Ostia at the mouth of the Tiber, had to defend the long coasts of Italy, and became a Mediterranean power. Eventually they controlled countries bordering the Atlantic and rivers like the Rhine, the Danube, and the Nile. Classes or fleets became a standard part of the armed forces of the Roman Empire.

However, they did not establish a “navy” as distinct from the army. In fact, just as there was no Roman army as such, but only separate groups of legions in different areas under commanders independent of each other, so, on an even more ad hoc basis than with the different exercitus of the provinces, fleets were commissioned for particular needs. They were not assigned to separate “admirals,” but came under the command of the ex-consul or ex-praetor in charge of the relevant provincial exercitus. But in the late republican period small squadrons might be assigned to praefecti, sometimes not of senatorial, but equestrian status. Only exceptionally were freedmen given command and this was done in order to take advantage of their desperately needed naval expertise. The specifically “naval” complement on board was drawn from the non-Romans in the empire. An inscription from the island of Cos (IGRR 1.843) illustrates the position on a typical warship in detail. It records A. Terentius Varro, the presbeutes or legatus in charge (in the First Mithridatic War of 84–82 bc), as “leading the whole fleet,” Eudamos (a Greek) as nauarchos (navarch) in command of the squadron, and specifies the other officers as a trierarchos, the captain, a kybernetes (Lat. gubernator), the helmsman or pilot, a keleustes (Lat. celeusta), the rowing officer, a proreus (Lat. proreta), the officer in the bow, a pentacontarchos, apparently a junior officer, an iatros (Lat. medicus), a doctor, and at least 20 epibatae or marines. The inscription breaks off before the oarsmen, eretai (Lat. remiges) are mentioned (if in fact they were).

Shipping and Infrastructure

The basic warship was a long, narrow galley propelled by oarsmen (and fitted with sails for easier movement when not actually engaged). The prow ended in an armored point for ramming enemy vessels. Ramming was in fact the standard mode of attack in ancient naval warfare. Before ramming, attempts might be made to weaken the crew of the enemy by shooting at them with arrows or by discharging artillery at the ship or trying to set it on fire. A special maneuver requiring great skill was to row parallel to the enemy craft close enough to shear its oars off. It was regarded as specially characteristic of the Romans to board enemy ships, engaging their crews in hand-to-hand battle, the marines involved being legionaries or specialized auxiliaries.

Smaller ships had one, two, or three banks of oars, being called monoremes, biremes, and triremes respectively. But bigger ones were also built, fours (quadriremes), fives (quinqueremes), sixes (hexaremes), and even larger. The warship par excellence was the trireme, which was perfected by the Athenians in the fifth and fourth centuries bc. A replica of one, the Olympias, was built in the 1980s. It was c. 37 meters long and 6 meters wide, with a crew of 170 rowers and 30 others. On a calm sea it could reach a speed of eight knots.

The Romans called a warship a nauis longa, a “long ship,” to distinguish it from the nauis oneraria or merchantman. In the republican period they built the larger vessels characteristic of the Hellenistic period. These survived into the imperial period: the fleet at Misenum had quadriremes, quinqueremes, and even a six, the Ops. But then smaller ships dominated, especially triremes and biremes. The latter were called liburnians after the people of that name in Dalmatia, who had developed a fast galley for piratical raids. Their main advantages were speed and maneuverability. They might be cataphract or aphract, decked or undecked. Most seem to have had rams (rostra, hence the phrase naues rostratae). Some were fitted with turres (turrets) on the forecastle from which missiles could be discharged. A ship was distinguished by its parasemum or insigne, its figurehead. The aplustre on the stern-post was usually ornamented. Most had a shrine where the Tutela or protecting deity was worshipped. The most commonly cited representations of Roman warships are on the Praeneste Relief (from Palestrina) in the Vatican Museum and those on Trajan’s Column. They are often portrayed on coins, but in a highly stylized form.1

Warships were given names. They might derive from the religious sphere, including personifications, like the hexareme Ops (“Plenty”) noted above, or from the emperor, like Augusta, or from victories, like Dacicus, or from mythical beings, like those in Virgil’s (Aen. 5.114ff.) description of the naval contest at the funeral games for Anchises: an apparent quinquereme is called Centaurus, the triremes Chimaera and Scylla, and a liburnian Pristis (a sea-monster).

Warships were accompanied by nauigia minora, lesser craft, especially scaphae, long boats or skiffs, and scouting vessels. Since only a few passengers could be accommodated on a warship, large numbers of troops were generally conveyed, often under escort, in naues onerariae or transports. Special vessels were designed for the transport of the cavalry’s horses, the hippagones (horses can be seen disembarking in Scene 34 on Trajan’s Column).

The construction of a war fleet demanded a large amount of raw materials, especially wood. That favored was the silver fir (abies alba), which was seasoned after felling. But, especially when invasion fleets were being built in remote territories, unseasoned wood might have had to be used. Ships built from it moved more slowly. There were many other essential materials, such as metal for nails, armoring, etc., pitch, resin, flax for sails and ropes, and much else.

Ancient warships were designed for short spurts at maximum speed. But food and a large amount of water had to be taken on board to prevent exhaustion and dehydration in the crew: at Actium Antony’s rowers used their drinking water in an attempt to quench the flames after their ships had been set alight (Cassius Dio 50.34). After a battle in 36 bc Agrippa was advised not to pursue the defeated too long so as not to exhaust his rowers (Appian, B. Civ. 5.108). If at all possible a war fleet would put in to land at night to rest and to replenish supplies. It has been calculated that a warship could not spend more than four days in continuous sailing.

Invasion fleets might be built in undeveloped areas on beaches or rivers, but normally the facilities of a harbor were used. In the early empire the classic form of harbor that came to be favored consisted of moles going into the sea with an artificial island built between them to break the force of the waves at the entrance (for construction methods cf. Vitruvius 5.12). When Pliny the Younger was invited to sit on Trajan’s consilium or Advisory Council at his villa at Centum Cellae (Civitavecchia) in Etruria he observed a harbor being constructed there (Epist. 6.31). Of the two moles the left had been reinforced while the right was still under construction. The artificial island in the center was being raised on a foundation of huge rocks. They were held in place by their own weight and formed into a rampart (“agger”). Piles or piers were surmounted onto the rocks: the island itself was to be laid above them. Rutilius Namatianus (Red. 1.239ff.) adds that there was an inner pentagonal basin.

As noted below, Octavian had built ships at Rhegium and Agrippa had built the Portus Julius near Cumae. Octavian had also had fleets built on the Tyrrhenian and the Adriatic coasts of Italy, as Caesar (Appian, B. Civ. 2.41) had done before him. As Augustus, Octavian decided to place permanent harbors in those seas, at Ravenna and Misenum. The latter site (still Miseno) was at the northern end of the Bay of Naples. Virgil (Aen. 6.162ff.; 233ff.) alerted his readers to its importance by describing the tomb Aeneas built there for the hero Misenus. It consisted of an inner harbor, now the Mare Morto, connected to an outer harbor by a narrow channel over which a wooden bridge was built. The naval headquarters was called the castra or camp: the fellowtownsman and heir of a scriba of the fleet who died on duty at Ephesus had him recorded there (ILS 2888). The small town at the site grew rapidly as many veterans from the fleet settled there and it was eventually raised to the status of a colony.

Ravenna was situated in a swampy area with many lagoons. Augustus had the site connected to the Po by a canal, the Fossa Augusta. He had an inner harbor constructed with a new suburb adjacent to it, called Classis, the current S. Apollinare in Classe. The headquarters was called the castra: a second-century papyrus (CPL 193) records a soldier from a quinquereme in the fleet having a transaction ratified there, “aktoum kastris klasses praitoriai Rabennatous” (Latin, but written in Greek lettering). Ravenna had been made a municipium in 49 bc. Rather anomalously its “mayor” or chief executive had the title of magister (ILS 6665). It became an important ship-building center: an early tombstone there (ILS 7725) records the death of a citizen who was a “faber naualis” or shipwright and he is shown building a ship.

The Late Republic

During the Civil War and the Second Triumvirate that succeeded it (47–31 bc), major battles were fought all over the Mediterranean area. This involved huge logistical problems connected with troop transfers, and the need to protect convoys with warships. An urgent problem was the securing of grain for the capital as rival dynasts attempted to cut off or facilitate the imports as it suited their purposes. The two most decisive engagements may be briefly considered. The first was fought off Sicily, between Octavian, Caesar’s adopted son, and Sex. Pompeius Magnus Pius (as he came to style himself ), the son of Pompey the Great. In 46 and 45 he had won some successes against the Caesarians in Spain and had been saluted Imperator, an acclamation entitling him to a triumph. In 43 the Senate put him in command of the fleet and the sea-shore of Italy. His title on coins was “praefectus classis et orae maritimae ex s(enatus) c(onsulto)” (BMCRR 2.560ff. [7ff.] = RRC 1.520 [511]). It is not known how his authority on the coast was defined in detail, or what land forces he had at his disposal, but his main duty would have been to secure the corn supply to the capital (which later he found it politic to interrupt). He expanded his fleet by enlisting refugees and fugitives, many of them slaves. As admirals (“praefecti classium”) he used freedmen of his father’s, especially (Cn. Pompeius) Menas (an abbreviation of Menodorus) and (Cn. Pompeius) Menecrates. They had presumably been of service in the Bellum Piraticum of 63.

The navy of Sex. Pompeius was superior to that of Octavian. His crews were better trained and his ships better built. In an initial engagement in 42 he defeated a close associate of Octavian, his legate Q. Salvidienus Rufus (Appian, B. Civ. 4.85). Sling-shots from the battle survive, hailing Rufus as imperator, “Q. SAL(uidienus) IM(perator)” (CIL 10.8337).

In 38 Octavian proceeded to build new fleets at Rome and at Ravenna in the Adriatic (Appian, B. Civ. 5.80). In 37 he received 120 ships from Mark Antony which his sister Octavia, then Antony’s wife, supplemented with ten further craft which were combined merchantmen – warships, called “phaseloi trieritikoi” by Appian (B. Civ. 5.95) and “myoparones” by Plutarch (Ant. 35).

But the major preparations were left to M. Vipsanius Agrippa, his long-time colleague, who was consul in 37. He did this in a new harbor, the Portus Julius, formed by joining the Lucrine and Avernian lakes on the coast of Campania near Cumae (Cuma): Virgil (Georg. 2.161–4) described the works. Agrippa was able to use the forests of the area for timber (Strabo 5.4, 5, 245). He levied soldiers and trained sailors (Vell. 2.79), at first on practice benches put up on the land (Cassius Dio 48.51). Octavian had manumitted 20,000 slaves “ad remum” (Suetonius, Aug. 16; Cassius Dio 48.49). Agrippa introduced modifications to the warships’ armaments. He developed a powerful grapnel (“harpago”) which could be fired from a catapult. It had a claw at one end and ropes at the other with which to draw the enemy vessel in. He also put high towers at both ends of the warships (Appian, B. Civ. 5.118; 106).

Social dissonance began to manifest itself in Sex. Pompeius’ navy. His senatorial colleagues took umbrage at the prominence of his freedmen admirals. He had given Menas charge of his forces in Sardinia and Corsica: Cassius Dio (48.45) says he acted like a governor (governing was a preserve of the senatorial order). Eventually, and this for the second time, Menas deserted to Octavian with a flotilla of 60 ships (Appian, B. Civ. 5.78; Orosius 6.18, 21). At this date Octavian’s key supporters were men of questionable social status (like Salvidienus Rufus, Agrippa, and T. Statilius Taurus; at Actium, however, Taurus was assigned land forces). He accepted Menas with alacrity, bestowing not only “freedom of birth” but even equestrian status on him (Cassius Dio 48.45): Suetonius (Aug. 74) says Menas was the only freedman ever admitted to Octavian’s table, but this of course was in this unsettled period.

In 36 Octavian set sail from Puteoli (Pozzuoli). The number of ships in his fleet – it included liburnians – had been reduced from 130 to 102 due to the death of many oarsmen during the winter, a rare reference to disease in the crowded warships of the time. He suffered further disaster in a storm.

Octavian owed his victory at Naulochus to Agrippa. He awarded him the rare naval garland, the “corona classica” (Velleius Pat. 2.81), which Virgil (Aen. 8.683f.) singled out and which appeared on coins (RIC 1.107f. [29; 32]; cf. 77 [170]). The Tenth Legion bore the title of Fretensis, “Of the Straits of Messina,” surely gained on this occasion.

But the main concern of the time was the impending conflict with Antony, who was based in Egypt. He started building ships, and one of his agents, who had the title of prefect, M. Turullius, was censured for cutting down sacred groves for timber. Octavian got kudos after Actium by having him executed (Valerius Max. 1.1.19). By 32 Antony had concentrated his land and sea forces in Greece round the Gulf of Corinth. He issued a series of coins with the names of his praetorian cohorts and legions on the reverse and on the obverse a galley with a standard on its prow. On a series of denarii three of the legions have cognomina, one, the XVIIth, that of Classica (BMCRR 2.526ff. [cxvff.] = RRC 539 [544]).

He was short of rowers: his trierarchs impressed men from all available sources in the area, including youngsters (Plutarch, Ant. 62). He was also troubled by defections and disease among the men (Cassius Dio 50.12; 15). Even though he burnt some of his ships, they were still undermanned in the battle (Plutarch, Ant. 64f.). The final engagement took place at Actium (Aktion) at the entrance to the Ambracian Gulf in northwest Greece (Plutarch, Ant. 66ff.).

Antony had assembled a fleet of 500 warships and a land army of 100,000 (i.e., some 20 legions) and 12,000 cavalry. Most of his ships appear to have been triremes, but he had larger vessels, up to eights and tens. Many had been provided with extra plating against ramming (Cassius Dio 50.32). He included an Egyptian squadron of 60 ships in his battle line. This was under the command of Cleopatra, who called her flagship the Antonias. Against the advice of his gubernatores he loaded sails onto the ships. Twenty thousand legionary infantry (four legions) and 2,000 archers were put on board.

Octavian was content with 400 ships, 80,000 infantry (i.e., 16 legions), and 12,000 cavalry: both sides had to be prepared for a land rather than a sea clash. The ancient sources for the battles are very sparse, but several authors seem to place emphasis on liburnians in Octavian’s fleet. Horace wrote a poem celebrating Maecenas sailing in one among the high bulwarks of the other ships (“ibis liburnis inter alta nauium/ amice, propugnacula” – Epod. 1,1f.). Vegetius (4.33) ascribed Octavian’s victory to his liburnians. In fact, there was a persistent tradition that his fleet contained swifter, more easily maneuverable vessels than Antony’s (Plutarch, Ant. 62). He put his friends or political advisers in “hyperetica,” “auxiliary boats” (Cassius Dio 50.31 – smaller than Maecenas’ liburnian?).

Exploits by subordinate commanders have been recorded. When Antony fled the battle one of the liburnians that gave chase was that of Eurycles the Spartan, whose father, “a pirate,” had been executed by Antony (Plutarch, Ant. 67): he was granted Roman citizenship. In a skirmish just before the main battle, Tarcondimotus of Cilicia – the stronghold of the pirates in Pompey’s day – who called himself Philantonius (RPC 1.3871) on his coins, was killed. Whether there were other auxiliaries involved at Actium besides Antony’s archers, his Egyptian squadron, and Tarcondimotus’ Cilicians and, on Octavian’s side, Eurycles’ Spartans, is not known. Many of the recent recruits in Antony’s legions were provincials from the East.

Octavian naturally drew the maximum propaganda benefit from his victory. A large monument was erected on the site of his base camp and dedicated to Neptune and Mars for peace gained by land and sea. It was decorated with rams taken from the ships captured from Antony.2 Many of Antony’s ships were burnt, but some were sent to Forum Julii (Fréjus) in Transalpine Gaul (Tacitus, Ann. 4.5).

Further prows from Antony’s fleet were displayed in Octavian’s triumph in Rome: Propertius (2.1.34, but cf. his dark reference [15, 44] to the bones of Romans being swirled round in the sea of Actium) records them coursing down the Sacred Way (the route of a triumph – “Actiaque in Sacra currere rostra Via”). They were attached to the new Rostra on the podium of the Temple of the Deified Caesar in the Forum (Cassius Dio 51.19), no doubt recalling those affixed to the original Rostra in the Forum from the ships of the Antiates whom Rome had defeated in 338 bc.


Two wars under Augustus involved large fleets. The first was that assigned to the prefect of Egypt, Aelius Gallus, in 24 bc. He had an army of 10,000 (i.e., two legions) and many auxiliaries (of which 1,500 are named) and built warships (“makra ploia”), not less than 80 biremes (“dikrota”), triremes, and other light boats (“phaseloi”), and 130 transports. Strabo ( criticized him for building a fleet while the Arabs did not have one, and for the time he wasted in so doing. His remit was to invade Arabia across the Red Sea. An intriguing papyrus fragment (P. Oxy. 2820) seems to imply that he (if not an earlier governor) had incorporated ships from Cleopatra’s navy into the fleet.

Drusus the Elder acquired an even larger fleet for his expedition in Germany east of the Rhine. It was also used for exploration (and intimidation): as Augustus said “classis mea,” “my fleet,” sailed as far north as the land of the Cimbrians (that is, Jutland, Res Gestae 26.4). After Drusus’ death Tiberius continued his combined land and naval incursions, as did Germanicus, who built a fleet of 1,000 ships in ad 16 (Tacitus, Ann. 2.6): it is not certain whether the otherwise unknown Anteius, who was placed in charge of the fleet, had the title of “praefectus classis.” Harbors used during these German wars have been recorded by archaeologists, most notably one at Haltern on the Lippe where there is a block of eight wooden ship sheds suitable for boats the size of liburnians.

Such fleets were not standing fleets stationed in the areas concerned on a permanent basis, but were specifically constructed for a particular war. As such they may be labeled “invasion fleets.”

The Italian Fleets

Augustus’ enduring contribution to the Roman navy was the stationing of permanent fleets in Italian waters. A possible precursor of this was his sending part of Antony’s fleet after Actium to Forum Julii, which he raised to the status of a colony, including Classica in its title. It is possible that Sex. Aulienus (ILS 2688), a distinguished equestrian officer and duovir or “mayor” of Forum Julii, who is called a “praef(ectus) classis,” commanded it, but its subsequent history is unknown. The Roman army contained several atypical auxiliary regiments, in which Roman citizens served, called cohortes classicae. They must have been formed from its personnel: certainly some of the earliest members of the cohorts gave their origo as Forum Julii. The considerations which led Augustus to base permanent fleets off Italy are not known. Tacitus (Ann. 4.5) merely lists “duae classes, Misenum apud et Rauennam” in his catalogue of the armed forces of the empire, while Suetonius (Aug. 49) says they were to protect the Italian seas. They were hardly intended to protect troop convoys, as the legions were increasingly being stationed on the frontiers and piracy, although not fully suppressed, was controllable.

Augustus’ action may not have been a complete innovation. In the later 60s bc there was a fleet large enough to be assigned to a consul in Ostia (Cicero, Leg. Man. 33) and after his defeat of the pirates Pompey (who had been assigned all “available” ships against them) proposed that a fleet be based off Italy as a deterrent against piracy (and that sufficient financing for it be voted – Cicero, Flacc. 30). L. Staius Murcus, who had governed Syria in 44, was given command of the fleet and supervision of the sea the next year (“qui classi et custodiae maris praefuerat” [Velleius Pat. 2.72]). Sextus Pompeius (whom Murcus had joined) seems to have acceded to a similar position. Appian (B. Civ. 4.84) says he took command of all the ships he could find in Italian harbors and Dio (46.40) says “the navy,” “to nautikon,” was assigned to him. If pressed, this language could imply remnants of an official fleet off Italy in the late republican period.

The size of the fleets stationed at Misenum and Ravenna is not known. Deductions have been made from the fact that Nero and his successors in the Year of the Four Emperors (68–69) created up to three legions (i.e., 15–18,000 men) from them. But at the same time new recruits were being drafted into the fleets: Tacitus (Hist. 3.50) names Dalmatians being sent to the Ravennate fleet.

The fleets were put to differing uses. Their deterrent effect upon piracy was important – Augustus claimed to have made shipping safe. On one occasion the crew of an Alexandrian corn vessel poured libations to him, proclaiming that they lived, and sailed, through him (Suetonius, Aug. 98). In Alexandria itself he was worshipped as “epibaterios,” the one on board (Philo, Leg. 151).

There appear to have been groups of sailors in Rome from an early date. Initially they seem to have been housed in the barracks of the Praetorian Guard (Josephus, Ant. Jud. 19.253). Later there was a Castra Misenatium near the Colosseum and close to the training school for gladiators and its armory and a Castra Ravennatium across the Tiber. Their skills were used at public entertainments. In particular they set up the awning in the amphitheater (HA, Comm. 15.6).

Naturally they were used politically. Sometimes covert operations were assigned to them rather than to the Praetorian Guard. This was notoriously the case when Nero murdered his mother Agrippina the Younger in 62. He entrusted the deed to a freedman of his,3 Anicetus (Tacitus, Ann. 14.3), whom he had appointed prefect of the Misene fleet. His chief assistants were a trierarch Herculeius and a “centurio classicus,” Obaritus (it may be noted that during the Pisonian Conspiracy in 65 an attempt was made to suborn a navarch of the fleet, Volusius Proculus – Tacitus, Ann. 15.51).

The groups of sailors mentioned above were not used for exploration, which was undertaken, if at all, by the invasion or provincial fleets. Nor were they involved in large-scale transport of men and supplies (until the second half of the second century ad: cf. AE 1956, 124).

Nevertheless, as Suetonius suggested, their function was basically military. It seems best to regard them as part of the immediate forces available to the emperor. This is clearly indicated by their title of Praetoria, which they had acquired by Domitian if not before. Like the lesser urban forces in Rome, they were an adjunct to the Praetorian Guard to be used when operation by sea was the most convenient approach.


The “admiral” or prefect of a fleet was initially either an imperial freedman – the emperors used freedmen in other high-ranking posts as well – or a member of the equestrian order. From the Flavian period onwards only those who had gone through the militia equestris were appointed. Such was Pliny the Elder, who had a distinguished career not only in the army but in financial administration as a procurator. His nephew, Pliny the Younger (Epist. 6.16; 20), described his death while prefect at Misenum (where “classem imperio regebat”). When Pliny the Elder observed the cloud forming during the eruption of Vesuvius in 69, he decided to investigate and ordered that a liburnian be prepared for him to cross the bay. When he received information about the increasing scale of the disaster he ordered other vessels to be prepared, quadriremes. Although hot ash and pumice stone were falling on his boat, he ordered the gubernator to continue making for the area of danger. However, he was eventually asphyxiated. In later times it was not unusual for the prefect of the Misene fleet to go on to become prefect of the Praetorian Guard.

The most senior officers below the prefect were the navarchs, trierarchs, and centurions. Their relationship is obscure. The titles of the first two were inherited from Hellenistic navies. They are distinguished on an inscription (AE 1925, 93) to Mindius Marcellus, “praefectus classis” under Octavian at Naulochus. A navarch is usually regarded as superior to a trierarch. This is suggested by their order on a diploma of 71 (RMD 205) which was issued to “nauarchis et trierarchis et remigibus” of the Ravennate fleet. The standing of a navarch is also implied in the list of witnesses to a diploma of 54 (CIL 16.3): the beneficiarius or special assistant of a navarch is placed above those of military tribunes. One approach has been to regard navarchs as commanders of larger vessels than those under trierarchs. But it seems clear that they commanded squadrons or other sections in a fleet, while trierarchs commanded single vessels (of any size). Some career patterns show promotion from trierarch to navarch (ILS 2846; cf. 2852, an “archigybernes” promoted to navarch). Later there was a post of “nauarchus princeps”: one (ILS 2842) was adlected among the duovirs or “mayors” of an Italian municipium. Another (ILS 2847) was promoted to a primipilate in a legion.

Navarchs and trierarchs could be of peregrine status as late as the third century: Ulpian (Dig. 37.13, 1) expressed the opinion that even so, by military law, they could make wills that were valid. “Centurion” is a term from the land army. Centurions on warships came initially from the legions. (In 56 bc, during the Gallic War, D. Brutus had put specially picked legionaries onto his ships – Caesar, B. Gal. 3.7–16.) The ships were under centurions, who were obviously superior to the captains and were in control of operations. A “centurio classicus” is known (ILS 2231), but he was “centurio legion(is) XXXXI Augusti Caesaris” and therefore served during the Second Triumvirate. Those on the diplomas – they appear from ad 70 onwards – were of course peregrine; a Thracian on CIL 16.12, an Illyrian on RMD 204, a Pannonian on RMD 205, and a Dalmatian on CIL 16.14. Centurion was becoming a standard term in the navy, but was applied not to men transferred from the legions, but to promoted peregrines analogous to the centurions of auxiliary regiments. For the early use of “land” terminology in the fleets see also the Illyrian who described himself as a “mil(es) de lib(urna) Triton(is) 7 (=centuria) M. Vetti,” “soldier from the liburnian Triton of the century of M. Vettius” (ILS 2826). A common formula was to call one’s ship a century as a Dalmatian did when he said he was “of the century of the trireme Minerva,” “centur. triere Minerua” (ILS 2838). In fact, recruits to the fleet seem to have been drafted straight into a century rather than assigned to a ship (P. Mich 8.490f ).

Like all armed forces those of Rome were very conscious of status. In 52 a governor of Egypt felt it necessary to lay down the law; he stated the position unequivocally – members of the fleet were not entitled to the same privileges as auxiliaries or legionaries (P. Fouad 1.21; cf. P. Yale 1528 = FIRA 3.171): they were called “hoi ek tou eretikou” or “he¯ ton kopelaton,” those of the oar. The first fleet diploma used the term “remiges” but interestingly the actual recipient was called a “gregalis” (a “land” term: caligatus and manipularis appear on inscriptions). The usual term, however, was miles. This was not just a polite convention, but a legal status, as Ulpian stated in the Digest (37.13.1 – “in classibus omnes remiges et nautae milites sunt”). However, the generic miles was generally replaced by classicus in contexts where it was important to distinguish sea from land soldiers. The term first occurs on a diploma under Domitian (CIL 16.32 of 86). But literary authors seem to prefer the form classiarius to classicus.

As far as the status of ordinary men in the fleet is concerned, Claudius took an important decision to give legal privileges to those who had served in the fleets (the period of service was fixed at a minimum of 26 years). He did this by formal decree (a constitutio) which was inscribed in bronze and duly displayed in a prominent position in Rome itself. The recipient could get an extract copied onto a folded piece of bronze, attested to by seven witnesses (the normal practice). This is usually called a military diploma.4 Basically the beneficiary received Roman citizenship for himself and his family. The first extant fleet diploma (ILS 1986 = CIL 16.1) was issued to “trierarchis et remigibus qui militauerunt in classe quae est Miseni.” It was made out for a “gregalis” (an army term), an ordinary rating, who was a Bessan (a Thracian people). It may be noted that not only the ordinary oarsmen but captains as well (trierarchi) received citizenship: accordingly some, if not all, of them were also of peregrine status. The diploma names the prefect of the fleet under whom they served, an imperial freedman, Ti. Julius Augusti lib(ertus) Optatus.

The question arises whether, besides the oarsmen and the sailors, there was a separate category of marine in the imperial navy. There appear to be occasional references to them. When staging a mock naval battle with 30 “naues rostratae” in Rome in 2 bc, Augustus deployed not only “remiges” but also one thousand “homines” or “men”: “men,” because, since they were gladiators or slaves, one could not apply the honorable term milites to them.5

The practice in actual sea-battles is difficult to ascertain since so few occurred in the early principate. However, there was a minor engagement during the Batavian Revolt of 69 when men from the Classis Germanica, feigning incompetence, defected: the remiges were in fact themselves Batavians (Tacitus, Hist. 4.16). They frustrated the operations of the “nautae.” These were probably specialists from the south, like the gubernator from Elaea in Asia (Çandarli) and the proreta or bow officer from Alexandria buried in Cologne (Colonia Agrippinensis, ILS 2828; 2827). There were also “propugnatores” or marines on board. Whether they came from the legions or the auxilia is uncertain. Similarly those who some months later “discharged light weapons” from the Roman fleet of Petilius Cerialis against that of Civilis were presumably also drawn from the land army (Tacitus, Hist. 5.23). Somewhat earlier in the year gladiators were used as “propugnatores” in a battle on the Po in “liburnicae,” presumably from the Classis Ravennas (Tacitus, Hist. 2.35).

But it seems clear that Augustus did not create a category of epibatae or marines as such for the fleet. Presumably, if serious engagements occurred as in the cases just discussed, commanders would have to turn to the land forces for actual fighters. This is not to say that fleet personnel received no military training. “Armorum custodes” or superintendents of armories formed a regular rank and recruits for the fleet bought weapons on enlistment (P. Mich 8.467f.).

The Provincial Fleets

Large fleets continued to operate away from Italy under Augustus, but these were “invasion fleets.” Eventually smaller fleets were stationed permanently in the provinces.

The northern fleets

A Classis Germanica is mentioned for the first time in 69 (Tacitus, Hist. 1.58) and a Classis Britannica in 70 (4.79). The first diploma issued to either fleet was RMD 216 of 98. It was made out for “classicis qui militant sub eodem [i.e., Imp. Traiano Aug. – Trajan was governing Germania Inferior at the time] praef(ecto) L. Calpurnio Sabino.” If the men’s 26 years of service is deducted from the date of issue, their recruitment can be placed immediately after the Batavian Revolt, in 72. However, various considerations, including the availability of warships for Domitius Corbulo’s naval operations against the Chaucans in 47 (Tacitus, Ann. 11.18) and the extent of the preparations for the invasion of Britain, suggest that the German and the British fleets go back to Claudius.

The headquarters of the German fleet was on a branch of the Rhine at Alteburg 3 kilometers south of Cologne (Colonia Agrippinensis) (although the site itself may have been used earlier by land forces). As noted above some of its rowers were Batavians and Julius Burdo, “Germanicae classis praefectus” (Tacitus, Hist. 1.58), could well have been a Batavian, like the Batavian noblemen commanding auxiliary regiments in the area. However, the “nautae” in the fleet were probably professionals from elsewhere.

The main base of the Classis Britannica was at Boulogne (Gesoriacum, later Bononia) in Gallia Belgica. In the second century the fleet had a second headquarters in Britain, at Dover (Dubris). Local involvement with repairing or building ships may be indicated by a dedication (RIB 91) at Chichester (Noviomagus Regnorum), which some regard as a possible landing place for a division of the invading fleet. With the authorization of the local king, already enfranchised, Ti. Claudius Cogidubnus, a guild of “fabri” set up a temple to Neptune and Minerva (the goddess of craftsmen). Does the choice of Neptune indicate that they employed their skills by sea as well as on land? Agricola made full use of the fleet in his campaigns in the north under Domitian (Tacitus, Agr. 24f.). With him in the lead boat it advanced northwards in conjunction with the land forces. “Pedes equesque et nauticus miles,” the legions, the cavalry (i.e., auxiliaries) and the rowers and nautae, were housed in the same camps. The fleet is said to have inspired terror in the British. A bizarre incident occurred during the campaigns. A newly recruited auxiliary unit, the Coh. Usiporum (Tacitus, Agr. 28; they came from a people east of the Rhine), mutinied. It seized three liburnians for the return to Germany and compelled the gubernatores on them to act as their helmsmen. As the normal strength of a cohort was 500, this would imply that they calculated more than 150 men to a liburnian (assuming that the regiment was at full strength).

After his final victory at Mons Graupius Agricola used the fleet for exploration: the “praefectus classis” was ordered to circumnavigate Britain (Tacitus, Agr. 38; cf. 10). He was assigned “uires,” “a force,” presumably land soldiers, as marines. Plutarch (Def. Or. 410a; 419e) mentions a friend of his, Demetrius of Tarsus, in Cilicia, a literary critic, who went on an official “mission to remote islands.” Presumably he was on board and presumably he was the Scribonius Demetrius who made a dedication (in Greek) to Ocean at York (Eburacum, the northern legionary headquarters at the time) (ILS 8861 = RIB 662f.). The distinguished jurist Javolenus Priscus served as iuridicus or senior legal officer under Agricola. One of the cases he heard involved a trierarch and an archigybernus, Seius Saturninus, who had given his son the evocative cognomen of Oceanus (Dig. 36.1.48 [46]). That the British fleet at this date had such a senior official in it implies that it was of considerable size.

The Danube

During his Illyrian campaigns prior to the battle of Actium Octavian deployed an invasion fleet on the Danube (Cassius Dio 49.37).

The later fleet there that gave refuge to the Sueban chieftain, Vannius (Tacitus, Ann. 12.30), in 50 was presumably the Classis Pannonica. It may be asked whether it is attested on a fragmentary diploma found near Zagreb (CIL 16.17 of 71) issued to a Pannonian. Since he had served for 26 years (rather than the 25 of auxiliaries) he must have been a member of a fleet. It could have been an Italian or any provincial fleet, but the context is entirely Illyrican which suggests that it was the Pannonian. If so, subtracting 26 from 71, the fleet could have been in existence in 45, five years before the Vannian incident. Its main base was probably at Taurunum (Zemun), at the mouth of the Sava in the Danube.

The Classis Moesica patrolled the Lower Danube. It is named on a diploma of 92 (CIL 16.37), with the title of Flavia, which was also borne by the Pannonica. Ninety-two minus 26 gives 56, a date under Nero. The names of two harbors on the Danube probably reflect some of the different types of boats it used. Ratiaria (Archer in Bulgaria) derives from ratis (OLD svv.), a raft (propelled by oars) as well as a type of flat skiff, with which pontoons could be built for river crossings. (There was a “ratis,” the Minerva, at Misenum – AE 1964, 103). Sexaginta Prista (Rusé) reflects the pristis (OLD 1c), a type of lembus, a fast vessel used for reconnaissance, but also for transporting troops: lembi were so used by Julian in crossing the Danube in 361 (Ammianus Marc. 21.9).

In the second century a group of Roman citizens settled at a “uicus classicorum,” a village of men from the fleet, under an official with the title of magister, at Halmyris (Murighiol) (AE 1988, 986ff.).

Fleets in the East

When Nero turned the kingdom of Pontus into a province, he took over the royal fleet to patrol the Black Sea as the Classis Pontica. Josephus (B. Jud. 2.367) says it comprised 40 ships. Its main port was Trapezus (Trabzon). The navarch, a Roman citizen, C. Numisius S[p. f.] Qui(rina) Primus (ILS 2824), who was priest of Augustus and duovir at nearby Sinope (Sinop), must have belonged to an earlier fleet: Agrippa had used its facilities in 14 bc during his expedition to the kingdom of Bosporus (the Straits of Kerch; Cassius Dio 54.24).

The Classis Syriaca is first heard of on a diploma of 119.6 Subtracting 26 years brings it down to 93. Its main base was at Seleucia Pieria (Kaboussié): in 75 an artificial tunnel and a canal to divert a river clogging the harbor were built there. Only legionaries and auxiliaries were involved (AE 1983, 927). The fleet is not mentioned, which seems strange if it had been in existence by that date. Detachments of the Misene fleet were also stationed at Seleucia. An interesting papyrus of 166 (FIRA 3.132 = CPL 120) records the purchase of a boy slave, “natione Transfluminianum,” i.e., from across the Euphrates, by an optio or deputy-centurion from a trireme, the Tigris, and a miles of the same ship. The guarantor was a “manipularius” or ordinary rating from another trireme: as he was illiterate, a “suboptio” acted for him. The rank of three of the witnesses, all from triremes, is stated: another “suboptio,” a centurion, and a “bucinator” or trumpeter. The proceedings were conducted in Latin “in castris hibernis uexillationis clas(sis) pr(aetoriae) Misenatium.” But the “misthotes quintanos Meisinaton,” the contractor for the poll tax involved, added his attestation in Greek.

The Egyptian fleet

The Classis Alexandrina seems to be attested under Gaius Caligula (Philo, Flacc. 163). Its rowers were referred to by the governor of Egypt under Nero. Classici were discharged from it in 86 (CIL 16.32), again pointing to its existence under Nero (86 – 26 = 60). During the Jewish Revolt of 70 Titus used “makra ploia” (Josephus, B. Jud. 4.659) to convey troops up the Nile.

A former masseur of Tiberius and Claudius, an imperial freedman, Ti. Julius Xanthus (ILS 2816), was a sub-prefect. A prefect in the second century, possibly during the Jewish Revolt under Trajan, L. Valerius Proculus (ILS 1341), was at the same time put in charge of the potamophylacia (cf. B. Alex. 13), a guard on the Nile responsible for the collection of customs: he eventually became prefect of Egypt.

A Classis Nova Libyca, the New African fleet (ILS 1119), is only known from a dedication by one of its trierarchs to a senatorial patron (ILS 1118) of his whom Lucius Verus and Marcus Antonius had appointed to deal with pressing problems in the corn supply.

Fleet personnel might be used in non-naval contexts. In the large expeditionary force described by Ps.-Hyginus a detachment of classici, protected by cavalry, was used for road-building (Mun. Castr. 24). Men from the Classis Germanica worked in the quarries in the Brohltal near Bonn (CIL 13.7719) and a vexillation of the British fleet worked on Hadrian’s Wall (RIB 1340; 1944f.). In the Antonine period “classici milites” were involved in the construction of a tunnel at Saldae (Bejaia) in Africa (ILS 5795).


To the Romans, the military meant the legions, brigades of Roman citizens commanded by senior senators. They realized that these needed supplementation, but organized the cavalry and light-armed troops they employed as “auxiliaries,” or supplementary troops, in alae and cohorts commanded by prefects of equestrian origin. Warships were even more peripheral. Permanent fleets were only established later. Like the auxiliaries the crews were of peregrine extraction and also commanded by equestrian prefects.

However, they were soon assimilated to Roman army patterns with a complicated series of ranks. They used Latin and were adept in the application of Roman legal procedures in their financial dealings. They tended to cling to their peregrine names, sometimes quoting them after their new Latin names (using the “quiet” formula). But their tombstones were Roman.

The emperors recognized their worth. After a quarter of a century of service (but ancient life expectancy was low) they were made full Roman citizens. Some returned as men of prominence to their home villages, others settled near their bases. The veteran classiarius was fully integrated into Roman society.


1 The sculptures are reproduced in the edition of Vegetius by Baatz and Bockius 1997, esp.

59, fig. 7; 52, fig. 3; and in Reddé 1986 (between pp. 662 and 665), figures 38, 45–47.

For those on coins, cf. Höckmann 1997, 213ff.; Orna-Ornstein 1995, 179ff.

2 Suetonius, Aug. 18. For the badly mutilated inscription on the monument cf. AE 1937,

  1. Murray and Petsas 1989, 137ff. has counted the number and size of the sockets for

the rams displayed and deduced that Octavian recovered some 330 to 350 ships, pointing

to the very heavy losses suffered by Antony.

3 The ship carrying Agrippina was to be struck by a liburnica. It had been tampered with

to facilitate it sinking. It was apparently a camara (Suetonius, Nero 34, 2), which was a

light vessel incorporating a covering such as was used by pirates on Pontus (Strabo 11.2,

12, 495; Tacitus, Hist. 3.47.3).

4 For fleet diplomas cf. Forni 1986; Pferdehirt 2002, 56ff.; for the early witnesses Saddington

1997, 157ff.; Saddington 2004.

5 Res Gestae 23. According to Tacitus, Ann. 12.56 in a similar spectacle on the Fucine Lake

in central Italy, Claudius deployed 18,000 “men whom he had armed,” i.e., gladiators,

on triremes and quadriremes propelled by the strength of remiges and the skill of gubernatores.

To prevent escape the fleet was surrounded by rafts on which some of the praetorian

guard (including its cavalry) stood guard and deployed artillery. The rest of the lake

was occupied by classiarii in tectis nauibus, i.e., boats from which marines could operate.

If so, were such persons supplied by a land force? (Whether the milites from the Classis

Rauennas buried at the lake [CIL 9.3891; ILS 2825] belong to this event or not is uncertain.)

For hoplitai and toxotai on ships of Trajan cf. Cassius Dio 68.26.2.

6 Eck, Macdonald, and Pangerl 2002, 427. This item needs to be added to Saddington

2001, 581 and 583.


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Syrien,” Chiron 32: 427–35.

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Integrationspolitik. Cologne, 293–321 = Mavors V (Stuttgart 1992) 419–49.

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Rankov, B. 1995. “Fleets of the early Roman Empire,” in R. Gardiner and J. Morrison (eds.),

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Gesellschaft in der Römischen Kaiserzeit. Fs. E. Birley. Stuttgart, 179–89.

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Zentralmuseums Mainz 35: 299–313.

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—— 2004. “Local witnesses on an early Flavian military diploma,” Epigraphica 66: 75–9.

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