The Eastern Mediterranean of the 11th century was an Islamic world in flux. Muslim prophecy foretold of a series of imams who would follow after the Prophet Muhammad. The last of these would fight alongside with ‘Īsā ibn Miryam (Jesus) against the Antichrist in an apocalyptic battle at the end of days, before creating paradise on Earth. In Sunni Islam, an imam is a cleric who reads the Qur’an and leads prayer, largely analogous to a Christian priest or minister or to a Jewish rabbi. In the Shi’a tradition, however, they must come from the House of the Prophet and be pure in word and deed. An imam is infallible, guided by God, and must be obeyed.
Shi’a Muslims, those who believe Ali (Muhammad’s cousin and son-in-law, husband of his daughter Fatima) was the rightful successor of the Prophet, consider Ali to be not just the Fourth Caliph, but also the First Imam. Each subsequent Shi’a imam was a descendant of Ali, and of Muhammad through his daughter Fatima. The majority of the world’s Shi’a population, then and today, believed that the Twelfth Imam would be the one to overthrow corrupt governments and establish peace. These Twelver Shi’a broke away from the Sunni Abbasid in the early 900s to form the Fatimid dynasty. Shi’a believe this messianic Twelfth Imam has already been born, as Muhammad al-Mahdi in 868 CE, and that God has hidden him away to protect him and prolong his life. This hidden period is known as “Occulation”.
The 10th century revival of 8th century succession disputes did not help Muslim unity. The Sunni caliphate in Baghdad was weakened, broken into small provincial rulings held by separate emirs with nominal loyalty to the central government. The Shi’a in northern Africa were initially strong, though ever splintering religious sects caused internecine warfare. However, when the Seljuk Turks swooped down from Central Asia in the 1050s, they completely upended the balance of power. These Sunni warriors conquered swaths of the Byzantine empire by the 1071 Battle of Manzikert. They went to war with the Abbasid caliphate, and in 1077 they captured Jerusalem from the Fatimid rulers. Adding to the chaos, a Fatimid prince had rebelled against his brother’s rule.
“Although Nizar was the rightful claimant to the throne after his father’s death, his younger brother Ahmad al-Musta’lī, supported by his father-in-law, the chief Vizier Badr al-Jamali, usurped all the power… Mustaali, feeling insecure during Nizar’s existence, plotted against Imam Nizar and finally succeeded in making him a prisoner along with his two sons.” – A.S. Picklay, History of the Ismailis
Furthermore, between 1092 and 1094 several key rulers died. These included the Sunni caliph of Baghdad, the founder of the Seljuk Empire, Malik Shah I, and the Vizier and strategic ruler of the Seljuks. Each of the three largest Muslim dynasties was reckoning with its own internal succession disputes and questions of rule, as well as engaging in border wars with one another, when the Crusaders stumbled into the Mediterranean. The Europeans imagined they were fighting a holy war, a religious war between Christianity and Islam. The Muslims they fought against did not conceive of the battles that way at all; if they had, they might have sought alliances with other Muslim states against the Crusaders. But each Muslim dynasty approached the Crusaders as simply another army on the map. The Crusaders benefited from a “divide and conquer” strategy because the Muslim was already fragmented.