In 644 Umar was assassinated in Medina, stabbed while leading the dawn prayer by Abu Lu'lu'a, a Persian captive said to have held a personal grievance. Dying, he appointed a council of six senior companions to choose his successor, from which Uthman emerged, an arrangement meant to avert a disputed succession.
His memory, like Abu Bakr's, divides the tradition. For Sunni Muslims Umar is the second of the Rightly-Guided Caliphs and the very model of just and incorruptible rule; stories of his nocturnal walks through the city to see that none went hungry became a template for the ideal of Islamic governance, and his conquests are seen as the providential spread of the faith.
Shia Muslims, holding that the succession rightfully belonged to Ali, regard the caliphates of Abu Bakr and Umar as a diversion of legitimate authority, and some Shia traditions view Umar critically for his role at the Saqifa and in the disputes that followed the Prophet's death. The assassin has even been venerated in some later Shia settings, a fact that has been a source of profound and sometimes violent friction between the communities. Here again the division is not about the man's competence, which few deny, but about the legitimacy of the office he held.