(1) ʿAli ibn Abi Ṭalib (c. 600 – 661 CE) was the last of four Rightly Guided Caliphs to rule Islam (r. 656–661) immediately after the death of Muhammad, and he was the first Shia Imam. The issue of his succession caused a major rift between Muslims and divided them into Shia and Sunni groups. His assassination in the Grand Mosque of Kufa by a Kharijite coincided with the rise of the Umayyad Caliphate. The Imam Ali Shrine and the city of Najaf were built around Ali's tomb and it is visited yearly by millions of devotees.