Early Islam experienced division over succession and interpretation of the Quran. Abu Bakr succeeded Muhammad and expanded Islam's influence, followed by Umar. Uthman's assassination led to a war between Ali's supporters and Muawiyah's supporters. Muawiyah took power after Ali's assassination, establishing the Sunni sect, while Ali's descendants formed the Shiite sect. Sufism later emerged as a mystical movement. Despite political divisions, Muslim civilization advanced science and knowledge, adopting Greek, Roman and Asian ideas and making major contributions to fields like geography, medicine and mathematics. European exposure to Muslim advances came through conquests in Spain and interactions during the Crusades.

1. Islam -Part III