The core of the Fatimid army emerged from the Berber Kutama tribe, who had accepted the Isma'ili propaganda of Abu Abdallah al-Shi'i and overthrown the Aghlabids of Ifriqiya between 902 and 909.

Very quickly the Kutama were supplemented with other ethnic contingents, such as the Rūm (Byzantine Greeks) and the Sudān (Black Africans), inherited from the Aghlabid military, but the Berbers remained the mainstay of Fatimid armies until the 970s, when the Fatimid conquest of Egypt and their subsequent expansion into Syria brought them into conflict with the Turkic ghulām cavalry of the eastern Islamic world.

Their regime was ended by the Armenian Badr al-Jamali, who instituted a quasi-military dictatorship under the guise of an all-powerful vizierate, which effectively reduced the Fatimid caliphs to puppets.

It began as a quasi-revolutionary force during its early decades, when it was marked by indiscipline and tribal rivalries, which resulted in the failure of the first attempts to conquer Egypt.

As the Fatimid regime consolidated itself, however, the army's quality improved, and during the conflicts of the 950s in North Africa and against the Byzantine Empire in Sicily, it performed well.

[2] The expenses of maintaining a standing army were enormous: in the words of the historian Claude Cahen, in the medieval Islamic world "the chief preoccupation, whether of the soldiers or of the power they served, was the provision for their pay (riqz, khubz)".

[3] Cahen stresses that detailed information is "scattered and inaccurate", but during the 10th century an infantryman in Iraq could expect a yearly pay of between 500–1,000 silver dirham, approximately two to three times as much as an artisan.

[7] The military's dissatisfaction over lack of pay was the main reason for the anarchy between 1062, which led to the virtual disintegration of both army and country, that lasted until the rise to power of Badr al-Jamali in 1073.

[4] As in other areas of the Muslim world using the iqṭāʾ system, it led to deteriorating quality of land, and after Badr al-Jamali came to power, he engaged in reforms aiming to address the problem.

[9] While previously the bulk of the army had been paid salaries directly from the dīwān, Badr al-Jamali's reforms generalized the use of iqṭāʾ for the upkeep of the soldiers.

[13] Following the model current in the Islamic world, the Fatimid army was originally divided into ethnic and tribal units, which also generally coincided with functional distinctions of light and heavy cavalry, infantry, etc.

[15] The latter title was borne by Badr al-Jamali when he came to power,[15] and henceforth designated the quasi-dictatorial viziers who ruled the Fatimid state almost without interruption until its end.

[21] Much more plausible are the figures given elsewhere by al-Maqrizi, referring to the late 1160s, during Shirkuh's arrival in Egypt: 10,000 cavalry, 40,0000 Black African infantry, and 10,000 marines and iqṭāʾ troops.

[2] This led to a reform under the Caliph al-Aziz Billah (r. 975–996), with the help of the vizier Ya'qub ibn Killis, and brought the Fatimid military more in line with practices in the eastern Islamic world, most notably in the use of Turkish ghilmān.

[31] On the other hand, this dominion of the semi-civilized Kutama was greatly resented, not only by the other Berber tribes, but chiefly by the inhabitants of the cities, where the Arabic culture predominated.

[39][40] Finally, when al-Hakim assumed the reins of government in 1000, he launched a purge of the Fatimid elites, during which Ibn Ammar and many of the other prominent Kutama were executed.

[42] Other Berber groups attested in the Fatimid army were the Bāṭiliyya or Bāṭilīs ('the Champions'), who participated in the conquest of Egypt and had a quarter of their own in Cairo.

The term normally denotes specifically Byzantine Greeks, but probably also included slaves of European origin bought or captured in raids in Italy and elsewhere.

Ṣaqlabī), a term frequently applied to European slaves in Islamic lands, but not tied to a specific ethnic or regional origin.

[57] However black troops were heavily used by the previous Egyptian regimes of the Ikhshidids and Tulunids, and the conquest of the county opened a more direct way of recruitment via the Nubian kingdoms to the south of Egypt.

[58] The al-Saʿdiyya were sufficiently prominent that Byzantine envoys visiting the court brought gifts specifically for them, but in 1005 al-Hakim suddenly, for reasons unknown, purged the unit, killing its commander and half of its 100 men.

[59] The influx of black soldiers upset the balance with the other groups, as well as relations with the civilian population, who were exposed to plundering and even killings at the hands of the ʿabīd.

[46] Al-Hakim put officers of the ʿabīd in command of the Turks in a deliberate move to humiliate the latter for their unruliness; the result was a major battle between the two groups in February/March 1020.

The situation was so bad, that the ʿabid were reportedly reduced to eating dogs, as they did not receive any pay; repeated riots and mutinies are recorded for the years 1024–25.

[51] When al-Mahdi Billah founded a new palace city at Mahdiya, they provided part of its garrison, and the extramural suburb where they lived became known as Zawila after them.

[70] The Daylamites (al-Daylam), a mountain people from northern Iran, were a common source of soldiers for a number of Islamic potentates already since the 9th century.

[69][71] Armenians had been serving in the armies of Middle Eastern powers for centuries, and began entering Fatimid service after the conquest of Egypt.

[23] The Kutama, which formed the mainstay of the Fatimid army during its early period, were armed with swords, bows, and especially the javelin, much as their forebears in classical antiquity.

Its division into ethnic corps meant that it lacked cohesion, while the fact that Black African infantry comprised the bulk of its troops limited its mobility.

As a result, the "Battle of the Blacks", where the Fatimid troops were defeated and driven to flee Cairo, was at least partly cast in religious terms as an attack on infidels.