Immediately after the Prophet's death in 632, Abu Bakr, as the first Caliph, continued the effort to abolish paganism among the Arab tribes, and also to incorporate Arabia into a region controlled by the political power of Medina.
When Muhammad died his successor Abu Bakr spread the Islam through military action and started the Riddah Wars, to keep breakaway tribes in the Islamic fold. Umar was the next successor and he extended military actions to Syria and Palestine. By taking these actions the Muslims conquered Egypt and North Africa. Also the Islam was accepted by tolerating other religions such as jews and Christians.
