Imamate
Imamate is the institution or doctrine of leadership in Islam. Sunni and Shia traditions differ over its basis, authority, and succession.
Sunni Islam: The largest branch of Islam, whose traditions recognize the first four caliphs as legitimate successors to Muhammad. Sunni thought generally treats imams as community leaders or prayer leaders, not divinely designated successors.
Muhammad: The founder of Islam, regarded by Muslims as God's final prophet. The question of who should lead the community after his death frames later doctrines of imamate.
Imamah (Twelver doctrine): The Twelver Shia doctrine that imams are divinely appointed, protected from error, and authoritative guides after Muhammad. It gives the most developed account of how Shia imamate confers religious authority.
Succession to Muhammad: The seventh-century dispute over who should lead the Muslim community after Muhammad's death in 632. The dispute established the historical setting for divergent doctrines of leadership.
Ashura: The tenth day of Muharram, observed by Muslims in varied ways and especially associated with mourning Husayn in Shia communities. Its commemorations keep Karbala and the moral claims surrounding imamate present in communal life.
Shia Islam: A branch of Islam that regards Ali and his descendants as rightful successors to Muhammad. Shia doctrines place the line of imams at the center of religious authority.
Ali: The cousin and son-in-law of Muhammad, the fourth caliph in Sunni tradition and the first imam in Shia tradition. His claim to leadership became the central reference point for competing accounts of succession.
Ismah: The doctrine of divinely protected impeccability or freedom from sin and error attributed to prophets and, in Shia theology, imams. Impeccability explains why Shia imams can serve as authoritative interpreters of religion.
First Fitna: The first major civil war in the early Muslim community, fought from 656 to 661. The conflict during Ali's caliphate intensified divisions over legitimate authority.
Arba'een: The fortieth-day observance after Ashura, marked especially by Shia pilgrims commemorating Husayn's martyrdom. The pilgrimage expresses devotion to the family of Muhammad and the memory of Husayn.