The Conquests

With the death of the Prophet Muhammad, a new era began, an era of vast conquests and the formation of a Middle Eastern–wide Arab-Islamic empire. The Arab-Muslim conquests began the processes that culminated in the formation of a new empire, which included all of the former Sasanian Empire and much of the Byzantine Empire, and in the emergence in that geographic and political framework of Islamic cultures and societies.

When Muhammad died in 632, he left no instructions concerning succession, and, in the absence of an agreement with regard to a successor, the Muslim community – a conglomeration of diverse elements – was on the verge of disintegrating. To prevent this, some of the tribes and factions elected Abu Bakr – one of Muhammad's closest associates and his father-in-law – as caliph or successor. Abu Bakr was the first of those who were later identified as the Rashidun, the Rightly Guided Caliphs: Abu Bakr (632–34), ʿUmar (634–44), ʿUthman (644–56), and ʿAli (656–61), who ruled by virtue of their personal connections with Muhammad and Arabian ideas of authority. The conquests made the caliphs the rulers of the newly conquered lands as well.