There was no single Islamic military system. Depending upon the geography, history, culture, and adversaries, different Islamic military traditions evolved. During the seven centuries of its evolution, before the Ottomans, however, some common identities appeared.
All early Islamic militaries were based on duality: an infantry and/or cavalry provisional army that was tribal or feudal, and a standing army that consisted of professional slave soldiers. During the foundation period of Arab-Islamic states, nomadic Arab tribes and to a certain extent villagers and city dwellers from the Arabian Peninsula were the only source of men for the army. Obviously by defeating Byzantine and Sasanian armies repeatedly, early Islamic armies showed that they were more than simply collections of tribal contingents. However, the tribal character persisted decades to come. These tribesmen tried very hard to protect their privileged military position by forbidding the conquered nations to provide men for the army. Moreover, by building distinct cities or districts removed from native populations they tried to protect their separate identity. These tribes were the backbone of the provincial army. Depending upon their tribal specialization they provided infantry and cavalry forces armed with the necessary equipment and weapons. In return, they received regular salaries from the central finance bureaucracy, which was created for this purpose. They also provided local administrative mechanisms and security troops. This emphasis on protecting a privileged military position, combined with keeping the population away from the military profession, was instrumental in creating another duality, which was a privileged, tax-free military class (Askeri) and a taxed civilian population (Reaya).
This system managed to function for only a century. The nomadic Arab tribes lost their martial fervor and military qualities soon after settling and mixing with the local population. Furthermore, with the conquest of the Persian Sasanids, for the first time they came across a highly professional and complex military system. Former Sasanid officers became naturalized and allowed in the Islamic armies. Due to the financial difficulties of raising cash regularly for the military salaries and because of Sasanid and Byzantine influences, a new system was introduced called the ‘‘Iqta.’’ This assigned the taxes of a certain land to individuals in return for providing military service. There were additional responsibilities to provide justice and order, and the Iqta gained a semi-feudal character.
The spiritual Caliphs were never able to control either the provincial army or the unruly royal guard units, which were ever anxious to protect their respective interests. In fact, the Umayyadid caliphs depended heavily on the Syrian army, thereby creating a large division between Syrian and Iraqi armies, which might have been the real reason behind their military weakness. Following this, the Abbasid caliphs established their regime with the help of another military group, the Khorasan tribes. But bearing in mind the experiences of the Umayyadid period they eliminated the Khorasan army after their victory. In order to build a powerful and centralized state they depended upon freedmen (Mawali) and military slaves (Ghulams). Actually, Mawali acted as a kind of precursor to formal military slavery. Although the Umayyadids already employed them before, it was the Abbasids who created a standing army based on slaves and freed slaves. The real value of the Ghulams was their total dependence upon their masters. Because they were foreigners in terms of ethnic origin and geography they did not have any local power base and relations with the local population. They did not have families to look after and were free to allocate all their time to the needs of the military. Their minds and bodies were molded according to the needs of their masters. Another important identity of the slave soldiers was their military expertise, which the provincial armies lacked. Enlisting different racial or ethnically compact groups to create different military branches or units was also an important element in creating both military cohesion and political checks and balances. They were mostly either sturdy infantryman from mountain regions like Dailam and Northern Africa or mounted archers from the steppes like Turcomans. Offsetting this, tension and hostility between ethnically dominated military branches was rampant, and occasional armed clashes were inescapable.
The original Ghulams were prisoners of war or bought from middlemen who procured them from other tribes or from border warrior groups. They were mature men with existing military skills, so they needed very little additional training. Al-Mutasim (833–842) changed this system drastically. He gathered younger slaves and trained them under capable commanders and instructors. He even built a separate city Samarra for his new army. He preferred Turkish slaves to the others because none of the ethnic groups had the same level of expertise and skill as the Turks possessed as mounted archers. They were so effective that even their image and presence were enough to keep law and order.
Even though Abbasids continued to enlist Ghulams from other ethnic groups, including even Christian Greeks and Armenians, they increasingly depended upon Turkish slaves who came from Central Asia and from north of the Caucasus. Unknowingly, the Abbasid caliphs introduced Turks into the Middle East with important powers. The Turks became not only very important but indispensable. Of course this Turkish military dominance created reactions and opposition from different circles, which was largely ineffective. Until the collapse of the Ottoman Empire, one of the most dominant forces of the Middle East would be Turkish military elites.
The Abbasid caliphs created the basis of the Ghulam system, which had an everlasting effect on all Islamic military systems. There were two key elements: military expertise and loyalty. The candidates were trained rigorously—including religious training—as an individual and as a part of their unit. They were isolated physically and culturally from everybody except the ruler and their unit. After this hard training and isolation, they became loyal only to the ruler and to their unit, which in a sense also became their family. Thus, isolation and training were the important parts of creating a trained and loyal army.
By creating a slave-based professional army, the Abbasids were also instrumental in creating, for the first time, a professional officer corps called the Quwwad (qaid is the singular form). The officers of the Abbasids were commissioned from the ranks of Ghulams, who had achieved distinction and had showed talent and capability. Because they depended upon their salary and because they came from nonaristocratic backgrounds, their professional advancement totally depended on their success in military affairs and their loyalty to the ruler.
The Iqta-based provincial armies did not disappear. In fact, they remained numerically the largest part of the military, vital in battle and in preserving law and order in the provinces. In terms of politics, power, and prestige, however, they were weak. The smaller slave-based standing army was instrumental to keep them loyal and obedient to the central government and especially the ruler himself. Even some governors, following the example of their rulers, founded slave units for themselves to preserve their position and gain more power. A product of creating private armies within the state was the bypassing of centralized command and control and the removal of the bonds of direct loyalty to the ruler. Some governors were successful in carving separate states for themselves by using their Ghulam armies, as in the examples of Tulunids and Ikhshidids of Egypt.
The Mamluks of Egypt perfected the Ghulam system by establishing a unique system of training and promotion and, in fact, because of this perfection Mamluk became the generic name of the whole slave military system. Actually, the foundation of the Mamluk state showed the inherent danger of this system. It was a successful system as long as the central state was financially strong, but when the state fiscal mechanisms faltered, political instability and financial crisis began. The Ghulams then became the decisive actor of the internal turmoil and, in fact, became king makers. With their solidarity and military power they assigned their favorites as rulers, and in this way they broke the code of loyalty. In the long run they also destroyed their solidarity and military effectiveness by spending most of their energy and time on politics and not on their profession.