Write a summary of the early spread of Islam. Please include events like Muhammad's death, the caliphs unify Arabia, Ali's election to the caliphate, the Muslim entry into Spain, and the Battle of Tours.
Answer: Most of Arabia was under Muslim control by the time Muhammad died. After his death, later caliphs unified Arabia and expanded Islamic territory across the Middle East and North Africa. The fourth caliph was Muhammad´s son-in-law, Ali. After his death, Sunnis and shi´ah split in a dispute over who should be the next caliph.
