Powers and Thrones: A New History of the Middle Ages

by Dan Jones

But in electing Uthman the council passed over the claims of Muhammad’s cousin Ali, and this decision would eventually have enormous consequences for the history of Islam and the wider world. During Uthman’s twelve-year caliphate, Muslim armies continued to press out ever farther east and west and to develop their fighting capability in the west. In the late 640s they campaigned in Armenia and eastern Asia Minor. In the east, they rolled ever farther through the disintegrating Persian empire, so that by 651 almost all of it was under Muslim control, with the frontier at the borders of what is now Afghanistan. Meanwhile, in the west, an army of forty thousand men began to chew through north Africa, stripping away Byzantine territory in the Exarchate of Africa, working their way at one point to within a few days’ march of Carthage.