Hasan ibn Ali was an Alid political and religious leader. The eldest son of Ali and Fatima and a grandson of the Islamic prophet Muhammad, Hasan briefly ruled as caliph from January 661 until August 661. He is considered as the second Imam in Shia Islam, succeeding Ali and preceding his brother Husayn. As a grandson of the prophet, he is part of the ahl al-bayt and the ahl al-kisa, and also participated in the event of mubahala.
Calligraphic seal featuring Hasan's name, on display in the Hagia Sophia
A view of the modern-day Kufa, the headquarters of Hasan, and its Great Mosque, where he gave his inaugural speech
Iranian Qajar dynasty tapestry, probably a Shia talisman, depicting Ali with Hasan and Husayn (Library of Congress)
Nineteenth-century painting of Ali (center), Hasan, and Husayn
The Alids are those who claim descent from Ali ibn Abi Talib, the fourth Rashidun caliph and the first imam in Shia Islam. Ali was also the cousin and son-in-law of the Islamic prophet Muhammad. The main branches are the Hasanids and Husaynids, named after Hasan and Husayn, the eldest sons of Ali from his marriage to Fatima, the daughter of Muhammad. As the progeny of Muhammad, they are revered by all Muslims. The Alids have led various movements in Islam, and a line of twelve Alids are the imams in Twelver Shia, the largest Shia branch.
Medallion bearing the name of Ali inscribed with Islamic calligraphy in Hagia Sophia, Istanbul, Turkey.