establish an independent realm in the eighth century; and, over the decades, the rift between the Sunni and Shi‘a strands of Islam gradually intensified. Communities of Shi‘ite Muslims continued to live, largely in peace, alongside and among Sunnis across the Near and Middle East. But in 969 a particularly assertive Shi‘ite faction seized control of North Africa. Championed by a dynasty known as the Fatimids (because they claimed descent from Fatima, Muhammad’s daughter), they set up their own rival Shi‘ite caliph, rejecting Sunni Baghdad’s authority. The Fatimids soon proved themselves to be potent adversaries–conquering large swathes of the Near East from the Abbasids, including Jerusalem, Damascus and sections of the eastern Mediterranean coastline. By the late eleventh century, the Abbasids and Fatimids regarded each other as avowed foes. Thus, by the time of the crusades, Islam was riven by an elemental schism–one that prevented the Muslim rulers of Egypt and Iraq from offering any form of coordinated or concerted resistance to Christian invasion.
Even as the enmity between the Sunnis and Shi‘ites hardened, the degree of influence exercised by both the Abbasid and Fatimid caliphs dwindled. They remained as nominal figureheads–in theory retaining absolute control over religious and political affairs–but in practice executive power came to be wielded by their secular lieutenants: in Baghdad, the sultan; in Cairo, the vizier.
A further, dramatic change transformed the world of Islam in the eleventh century–the coming of the Turks. From around 1040, these nomadic tribesmen from Central Asia–noted for their warlike character and agile skill as mounted archers–began to seep into the Middle East. One particular clan, the Seljuqs (from the steppes of Russia, beyond the Aral Sea), spearheaded the Turkish migration. Having adopted the religion of Sunni Islam, these fearsome Seljuqs declared their unswerving allegiance to the Abbasid caliph and readily supplanted the now sedentary Arab and Persian aristocracy of Iran and Iraq. By 1055, the Seljuq warlord Tughrul Beg had been appointed as sultan of Baghdad and could claim effective overlordship of Sunni Islam; a role which members of his dynasty would hold as a hereditary right for more than a century. The advent of the Seljuq Turks brought a new, vital lease of life and unity to the Abbasid world. Their restless energy and martial ferocity soon brought sweeping gains. To the south, the Fatimids were driven back and Damascus and Jerusalem reconquered; notable victories were scored against the Byzantines in Asia Minor; and a Seljuq splinter group eventually founded their own independent sultanate in Anatolia.
By the early 1090s the Seljuqs had reshaped the Sunni Muslim world. Tughrul Beg’s able and ambitious grandson Malik Shah held the office of sultan and, together with his brother Tutush, enjoyed relatively secure rule of Mesopotamia and most of the Levant. This new Turkish empire–sometimes referred to as the Great Seljuq Sultanate of Baghdad–was forged through ruthless despotism and the presentation of the Shi‘ites as dangerous, heretical enemies against whom Sunnis must unite. But when Malik Shah died in 1092, his mighty realm quickly collapsed amid succession crises and chaotic civil war. His two young sons fought to be named sultan, contesting control of Iraq and Iran; while in Syria, Tutush sought to seize power for himself. When he died in 1095, his sons Ridwan and Duqaq likewise squabbled over their inheritance, snatching Aleppo and Damascus respectively. At this same time, conditions in Shi‘ite Egypt were little better. Here, too, the precipitous deaths of the Fatimid caliph and his vizier in 1094 and 1095 brought sudden change, culminating in the rise of a new vizier of Armenian heritage, al-Afdal. Thus, in the very year that the crusades began, Sunni Islam was in a turbulent state of disarray and a new ruler of Fatimid Egypt was