EP.22--History: Abu Bakr, Umar, and the Arab Conquests

After Muhammad's death in 632 CE, the question of the leadership of the community will prove to be a serious challenge for Muhammad's followers. Nevertheless, within a few decades, the Arab armies will be in control of Iraq, Iran, Syria, Egypt, North Africa, Spain, Central Asia, and the Indian Subcontinent, and will establish a large empire.

Sources and Further Reading:

The History of al-Tabari
The Venture of Islam         by Marshall G.S. Hodgson
The Early Islamic Conquests       by  Fred M. Donner