Cousin and son-in-law of the Prophet, fourth Rashidun Caliph (656-661) and first Imam in Shia tradition. Assassinated by Ibn Muljam in the Great Mosque of Kufa on 21 Ramadan 40 AH (Jan 661); buried in Najaf. The shrine was repeatedly expanded, from Harun al-Rashid to Shah Abbas and Nadir Shah's gilding (1743). (Sources: TDV 'Ali'; Wikipedia/Structurae.)