As Islam spread, it began to encompass a plurality of peoples, both Arab and non-Arab. This created conflict because Arab Muslims, by and large, considered themselves superior to non-Arabs. When Uthman was murdered in 656, the question of leadership again arose.
The problem was that nothing in Mohammed's recitations dictated how leadership of the ummah should be determined. Ali, Mohammed's cousin and son-in-law was chosen as caliph. He was the first Muslim leader to call for equality for non-Arab Muslims. His right to rule was contested by Mu"awiyah, then the governor of Syria. This led to Islam's first civil war.
Both agreeing to let Allah decide, they battled at Siffin. When the battle was inconclusive, it forged a schism through the Muslim people. Many thought that Ali was the rightful leader because of his connection to the prophet. When Ali died, it became a moot point, and Mu"awiyah started what would become the Umayyad dynasty. .
Under Mu"awiyah, the capital of the burgeoning empire was moved from Mecca to Damascus, and Mu"awiyah began to adopt Byzantine administrative practices. While his administration brought some prosperity and stability, the belief among Arab Muslims that Islam was a Arab religion became increasingly fractious. This disagreement between Arabs and non-Arabs led to the overthrow of the Umayyad empire in 750 and led to the creation of the Abbasid Empire.
Under Abbasid control, the nation flourished. It brought unprecedented prosperity, political stability, and a breath of change into the region's zeitgeist. Equality for all Muslims was mandated, and a Muslim's options greatly expanded. No longer was every Muslim virtually destined to become a warrior. With a more stabilized government, its capital now moved to Baghdad, the warrior class made room for more cosmopolitan occupations including bureaucrats, artisans and scholars.
As Islam continued to grow, leadership continually came into question and eventually divided Islam into two major sects.
