Umar ibn al-Khattab

Umar ibn al-Khattab was the second of the four caliphs whom Sunni tradition calls "Rashidun" (rightly guided), ruling roughly 13-23 AH / 634-644 CE. He belonged to the Banu Adi clan of the Quraysh, the leading tribe of Mecca. His traditional birth year (c. 584 CE; some sources give c. 586) is an estimate; modern historians treat pre-Islamic Arabian dates as approximate. Reports hold that Umar first opposed Muhammad and then converted (traditionally c. 615-616 CE), after which he became a prominent figure among the early Muslims; he is later given the epithet al-Faruq ("the one who distinguishes truth from falsehood"). In 622 CE he took part in the Hijra (emigration) to Medina and became a close adviser to Muhammad and then to the first caliph, Abu Bakr, who is reported to have nominated him as successor. As caliph, Umar adopted the title amir al-mu'minin ("commander of the faithful"). His reign saw the rapid expansion of Muslim rule into the Sasanian (Persian) and Byzantine lands, and tradition credits him with administrative measures such as the diwan (a register for distributing stipends), the founding of the garrison towns of Kufa and Basra, and the dating of events from the Hijra — though the extent of his personal agency in each is uncertain. Sunni tradition reveres him as a model of justice; in the Twelver Shia view, by contrast, his accession is contested in favor of Ali. He was fatally stabbed in Medina in 23 AH / 644 CE by Abu Lu'lu'a, an enslaved Persian.