A term collectively applied to a number of Muslim sects that assert the primacy of the family of Muhammad, as represented by the Prophet’s son-in-law, ‘Alī ibn Abī Tālib (d. 661) and his descendants.
The actual Arabic term is shi‘at ‘All (party of ‘Alī), which seems to have been used as early as the civil war during ‘Alī’s caliphate (656-661). After ‘Alī’s death the Shī‘ites continued to agitate on behalf of his family, and Shī‘ite rebellions caused considerable concern for both the Umayyad (661-750) and ‘Abbāsid (750-1258) caliphates.
Shī‘ite doctrine is characterized most particularly by the recognition of the imams: individuals regarded as the spiritual leaders of the Muslim community. Each imam was meant to guide the Muslim community, a task in which he was assisted by the teachings of the one who designated him and by a closer connection to God, achieved through ilhām (divine inspiration). Shī‘ites believe that Muhammad designated ‘Alī as the first imām, with a number of imāms following him. Over time the Shī‘ites split into a number of subdivisions, each with their own doctrines and practices. One of the main features distinguishing between them was the number of imāms they recognized. Some Shī‘ite groups still recognize living imāms today, while others regard them as currently being hidden from the world. Several of these groups were important in the Muslim world during the period of the crusades.
The Ithnā‘ashari Shī‘ites, often known as the Twelvers, or Imāmis, recognize a line of twelve imāms, starting with ‘Alī and passing down through his family. They believe that after the death of the eleventh imām, al-Hasan al-‘Askārī (d. 874), his son, named Muhammad, went into a state of ghaybah (occultation), communicating with the world through a line of four emissaries. After the death of the last of these in 941, the imām entered a state of ghaybah kubra (greater occultation). This will last until the end of time, when he will return as the mahdi (“guided one”), or messiah. During the period of the crusades, many Bedouin tribesmen of the Near East were Ithnā‘ashari Shi‘ites.
The Ismā‘ilis, sometimes known as the Seveners, were a Shi‘ite sect that claimed that the sixth imām, Ja‘far al-Sādiq (d. 765), had nominated his son Ismā‘il as his successor. When Ismā‘il died in 755 before his father, Ismā‘il’s supporters recognized his son Muhammad as the seventh and final imām, maintaining that he would also reappear as the mahdi at the end of time. They existed in secret until the middle of the ninth century, before emerging as two movements known collectively as the Ismā‘ilis. The first of these, known as the Qarmatians, attained particular prominence in eastern Arabia in the ninth and tenth centuries. However, it was the second movement, the Fātimids, that was particularly important in the history of the crusades. The heads of the Fātimiddynasty, diverging from earlier Ismā‘ili thought, claimed to be both rightful caliphs and true living imāms descended from Muhammad ibn Ismā‘il. They established themselves at Kairouan in North Africa in 909 and then moved their power base to Egypt after conquering al-Fustāt in 969. They built Cairo, from which they ruled until 1171, when their caliphate was suppressed by Saladin.
The Assassins, or Nizāris, owe their origins to a Persian propagandist of the Fātimids named Hasan-i Sabbāh (d. 1124), who in 1090 seized the fortress of Alamut in northern Persia. From there he began a program of Fātimid propaganda and political assassination. In 1094 the Fātimid caliph, al-Mustansir, died; he had nominated his eldest son, Nizār (d. 1095), to succeed him, but the palace administration ousted and murdered Nizār in favor of his more pliable brother al-Musta‘li (1094-1101). Hasan-i Sabbāh and his followers had sided with Nizār and became independent from the mainFātimid administration. During the years that followed, the Assassins established a hierarchical sect and continued to expand their sphere of influence, taking several fortresses in Persia and Syria. After 1162 the masters of the Persian Assassins claimed to be descendants of Nizār and hence the rightful imāms, a claim that they generally maintained until their Persian strongholds were destroyed by the Mongols in 1256. The Syrian Assassins survived slightly longer, the last of their fortresses falling to Baybars I, the Mamlûk sultan, in 1273.
In addition to the belief in the doctrine of the imāms, Shi‘ite doctrine and practices show a number of other differences from those of Sunni Muslims. In their interpretation of the hadith (reports of the sayings and actions of the Prophet and his companions, constituting a source of Islamic law), they give greater importance to accounts attributed to ‘Ali and his family; they reject the use of consensus in their interpretation of the law but give reason a greater role in their theology; not surprisingly, they place greater emphasis on the teachings of the imāms, as passed down through the jurisprudents; and most importantly for the period of the crusades, for the Shi‘ite groups that believe in a hidden imām, the offensive jihād (holy war) is considered to be suspended, as only the imām may lead it.