A massive programme of propaganda, of which the Forum complex was only a part, celebrated the victory in Dacia. Had Trajan simply wanted military glory to confirm his position as emperor, it is unlikely that he would have sought other opportunities for aggressive warfare. His rule was as popular as that of any emperor, and subsequent generations preserved his memory as the Optimus Princeps, the best of emperors, only rivalled in prestige by Augustus himself. His relations with the Senate – always the most critical factor in determining a ruler’s treatment in our literary sources – were generally very good, his rule considered both just and successful. Even Trajan’s vices – he was prone to infatuations with boys and youths – were pardoned, since his behaviour never reached a stage which Romans considered excessive or made him vicious. His decision to launch an invasion of Parthia in AD 114 was, according to Dio, motivated by a desire to win renown.
Trajan had spent more of his life with the army than most Roman aristocrats, and certainly appears to have enjoyed the military life. The pretext for war was, once again, a dispute over the relationship of the Armenian king to Rome, for a new monarch had been presented with his diadem of authority by the Parthian ruler and not by a Roman representative. The peace with Parthia had always been uneasy, since for the Romans their eastern neighbour represented a deeply unsatisfactory thing – the former enemy who had not been reduced to subordinate status and remained fully independent and strong. Trajan appears to have planned to win a permanent victory, for his campaign was from the beginning far more than simply a struggle to show dominance over Armenia. Massive Roman and allied forces – some seventeen of the thirty legions went in their entirety or as a substantial vexillation to the war – were backed by huge quantities of supplies which had been massed in the east for several years in preparation for the conflict. At the back of his mind the emperor was eager to emulate the great conquests of Alexander in the very region through which the Macedonian king had passed centuries before. The culture of the Roman Empire was firmly Greco-Roman and the heroes of the Hellenic world every bit as worthy of emulation as earlier generations of Romans.
Trajan’s eastern war began well, as in successive years he overran Armenia, Mesopotamia and most of Parthia itself. The Parthian capital of Ctesiphon and the major city of Seleucia were both captured, after which Trajan sailed down the Tigris to reach the Persian Gulf. If Trajan had any plans to follow further in the footsteps of Alexander – and it seems unlikely that he did – these were then dashed when major rebellions erupted throughout his newly acquired territories in AD 116. Roman columns had to operate throughout the new provinces, putting down insurrection. Matters were made worse by a major rebellion by the Jewish communities in Egypt and other provinces – though not Judaea itself – which required substantial numbers of troops to defeat. Trajan himself began a siege of the desert city of Hatra in Arabia. During the siege, when his own guard cavalry took part in at least one of the assaults, Trajan himself was almost struck by a missile as he rode past the walls. Dio notes that the emperor was not wearing any symbols of rank, hoping not to stand out amongst the other officers, but his age – he was now 60 – and grey hair made his seniority clear. He was missed, but a cavalryman riding beside him was killed. Hatra withstood the Roman onslaught until Trajan’s men, desperately short of water and other provisions, withdrew. The emperor was planning fresh operations when he suffered a stroke and died soon afterwards.
Trajan was succeeded by his relation Hadrian, but there was considerable doubt over whether in fact he had formally nominated him before he died. Thus, at the beginning of his reign, Hadrian’s position was somewhat insecure, making him reluctant to spend several years away from Rome fulfilling his predecessor’s eastern ambitions. This, combined perhaps with a feeling that Rome’s military resources were overstretched, led to the abandonment of the territories taken from the Parthians. Another casualty was Trajan’s great bridge across the Danube, which was partially demolished to prevent its ever being taken and used by an enemy. There were to be no wars of conquest during Hadrian’s reign from AD 117 to 138, and in most cases the wars which developed in response to rebellion or attack were fought by the emperor’s legates without his on-the-spot supervision. Lacking Trajan’s aggressive ambitions, Hadrian nevertheless spent much of his reign touring the provinces and in particular visiting and inspecting the army. Dio noted that he ‘subjected the legions to the strictest discipline, so that, though strong, they were neither insubordinate or intolerant’. A cult of Disciplina – one of a number of Roman deities personifying virtues – flourished in the army at this time, especially with the troops in Britain and Africa, and may well have been encouraged by Hadrian himself. Even when the army was not at war, the emperor could still conform to the ideal of the good general by ensuring that the troops were well trained and ready to fight if necessary. According to Dio:
He personally viewed and investigated absolutely everything, not merely the usual appurtenances of camps, such as weapons, engines, trenches, ramparts and palisades, but also the private affairs of the men serving in the ranks and of the officers themselves – their lives, their quarters and their habits – and he reformed and corrected in many cases practices and arrangements for living that had become too luxurious. He drilled the men for every kind of battle, honouring some and reproving others, and he taught them all what should be done. And in order that they should be benefited by observing him, he everywhere led a vigorous life and either walked or rode on horseback on all occasions … He covered his head neither in hot weather nor in cold, but alike amid German snows and under scorching Egyptian suns he went about with his head bare. In fine, both by his example and his precepts he so trained and disciplined the whole military force throughout the entire empire that even to-day [i.e. a century later] the methods introduced by him are the soldiers’ law of campaigning.
Hadrian watched the troops on exercise, just as a commander did in battle, praising and rewarding skill and criticizing and punishing poor performance. An inscription set up by an auxiliary soldier named Soranus survives, recording – albeit in rather poor Latin verse – an incident when the emperor commended his skill as an archer. Much fuller inscriptions found at Lambaesis in North Africa include selections from a number of speeches delivered at a parade of the provincial army as a culmination to a series of rigorous exercises. Hadrian’s style is very direct, referring to Legio III Augusta as ‘his’ legion and its commander as ‘his’ legate. He shows a detailed knowledge of the legion’s recent history, noting that it was seriously under strength through having detached a cohort for service in a neighbouring province. He also mentions that it had subsequently sent a cohort, strengthened by men drawn from the rest of the unit, to reinforce another legion. Stating that under such conditions it would have been understandable if III Augusta had failed to meet his high standards, he reinforces his praise by declaring that they had no need of any excuse. The centurions, especially the senior grades, are singled out for specific praise. Both in this section of the speech and in those parts delivered to individual auxiliary units, the emperor repeatedly pays tribute to the diligence of the legate Quintus Fabius Catullinus. His address to the cavalry element of a mixed cohort (cohors equitata) gives a good indication of the style of these speeches:
It is difficult for the cavalry of a cohort to put on a pleasing display anyway, and especially difficult not to displease after an exercise performed by an ala; the latter fills a greater expanse of plain, has more riders to throw javelins, makes frequent wheels to the right and performs the Cantabrian ride in close formation, and, in keeping with their higher pay, has superior horses and finer equipment. However, you have overcome these disadvantages by doing everything you have done energetically, in spite of the hot temperature; added to this, you have shot stones from slings and fought with javelins and everywhere mounted quickly. The special care taken by my legate Catullinus is very obvious…
Some criticism is contained in the speeches, for instance when a cavalry unit is reprimanded for pursuing too quickly and falling into disorder which would have made them vulnerable to a counter-attack. Yet overall Hadrian sought to encourage his soldiers and make them feel that they and their units were valued and respected. Apart from the specific details there is little that would seem out of place in a similar address by a modern general or manager.
Hadrian’s successor Antoninus Pius was not a military man, and spent no time on campaign. It was a mark of the security of the time that he was content to trust his legates to fight the major conflicts of the time. These were all in response to problems on the frontiers. From the late first century AD the military bases on the fringes of the Roman Empire had taken on more and more of an air of permanence, with old timber fortifications and internal buildings being replaced by stone. Hadrian had taken the process further in his visits to the provinces, ordering the construction of new installations and frontier boundaries. In Northern Britain the army laboured to construct the Wall which bears his name and stretched for 80 Roman miles from coast to coast. Such barriers were only ever intended to restrict outsiders, and never to hinder the movements of the Roman army, instead providing them with secure bases from which to launch aggressive operations. Rome sought to dominate its neighbours, not merely to repel any invasion or raid on the provinces, but attempts at permanent occupation of new territory were rare.