Islam 7th century
Arabia is the home of the world's third great monotheistic religion. Islam brings a message of the truth about the one God as revealed to the Messenger of God, Muhammad. Islam means 'surrender' (to God). Anyone who follows Islam is a Muslim. The archangel Gabriel appeared to Muhammad, commanding him to repeat the words of God. Muhammad has additional revelations. Muhammad preached in Mecca about the existence of one God, all-powerful and merciful. He also acknowledged that Abraham, Moses, and Jesus preached the same truth. Monotheism was not popular with merchants. Muhammad made enemies among the traders of Mecca, whose livelihood depended on idols. They planned to assassinate him, but he escaped to the town of Yathrib.
Muhammad and the Muslim era from 622
The Muslim era dates from the Hegira - Arabic for 'emigration', from Mecca to Yathrib, which welcomed Muhammad and his followers. Yathrib was renamed Madinat al Nabi, the 'city of the prophet', known as Medina. Muhammad built a following, severing as their religious, political, and military leader. He preached the words of God collected into the Qur'an (Koran).
The Muslims and Mecca 624-630
Battles broke out between Mecca and Muhammad’s troops. Muhammad persuaded the Meccans to allow his followers to make a pilgrimage to the Ka'ba and the Black Stone. On this first Muslim pilgrimage to Mecca, Muhammad's followers departed peacefully after three days. The following year the Meccans broke a truce, so the Muslims attacked the city. They captured Mecca almost without resistance. The Meccans accepted Islam. Muhammad cleaned the Ka'ba of idols, and he declared pilgrimage to the Ka'ba as a central feature of the new religion. Mecca had become the holy city of Islam. Muhammad and his most trusted followers still lived in Medina, which served as the political center of the developing Muslim state. Muhammad died two years after the reconciliation with Mecca. Muhammad was survived by three children, including a daughter Khadija.
Muhammad and the caliphate from 632-656
There was no clear successor to Muhammad. His father-in-law, Abu Bakr emerged as 'khalifat rasul-Allah,' meaning 'successor of the Messenger of God.' Under his leadership Muslim armies controlled Arabia up to the border of Palestine. Abu Bakr was succeeded by Omar (another father-in-law), who captured Jerusalem. Omar was killed in the mosque at Medina. Othman, the third caliph, was Muhammad’s son-in-law who conquered more land before his assassination. Ali, another son-in-law, became the fourth caliph. At this time there was a major sectarian split in Islam, between Sunni and Shi'a.
Ali spent most of his reign in conflict with other Muslims. The governor of Syria fought him to avenge Othman’s murder. Ali was assassinated.
Source: History of Islam, page 1
Gascoigne, Bamber. HistoryWorld. From 2001, ongoing.