He now demanded retribution against Uthman's killers.

In the aftermath of Uthman's assassination, Medina proved ill-suited to serve as a political and military base. Remote from the main centers of Arab population in Iraq and Syria and dependent on Egyptian grain supplies, the city could not sustain large-scale mobilization during the emerging conflict. Ali therefore moved the seat of his caliphate from Medina to Kufa, a major garrison city in Iraq, where larger concentrations of troops and provincial support