Database: Abbasid Army
The Abbasid caliphs maintained an expansive professional army. Its main tasks were to defend rather than expand the borders of the already enormous empire and to ensure the continuous rule of the dynasty.
In keeping with the Abbasid empire's ethnic diversity, the caliphal army included regiments of various origins. In the eighth century, soldiers coming from Khurasan (Eastern Iran and Uzbekistan) who had supported the Abbasid’s rise to power were the most common in the army, while other units included Arabs established in garrison cities and Zanj warriors from south-eastern Africa. In the ninth century, the Khurasani, considered too dangerous after their involvement in the 811-813 civil war, were replaced with ghilman regiments of Turkic, Slavic, and Caucasian slave-soldiers.
This professional army amounted to tens of thousands of troops settled in mostly urban barracks all around the empire. Among them, a small majority were infantrymen equipped with spears, axes, composite bows, and round helmets. The rest were an elite cavalry of chain-armored riders, armed with spears, axes, recurved swords, and bows. In battle, they would mount devastating armored cavalry charges from behind an infantry screen. But most combat involved small border raids and sieges in which a few hundred Abbasid soldiers fought similarly-armed Byzantine, Tang, or North African counterparts.
In time, they revealed themselves to be just as adept at securing enormous financial and political advantages for their own gain as their Khurasani predecessors. When Caliph al-Mutawakkil tried to curb these advantages in 861, he was murdered by his own guards, opening a period of anarchy in which different factions within the military vied for influence and control, setting up and toppling caliphs as they went. The Abbasid empire never really managed to settle down after this chaotic time.