Abu Bakr

Abu Bakr , 573-634, 1st caliph, friend, father-in-law, and successor of Muhammad. He was probably Muhammad's first convert outside the Prophet's family and alone accompanied Muhammad on the Hegira. The marriage of Abu Bakr's daughter Aishah to Muhammad made the ties even stronger. On the Prophet's death in 632, Umar secured Abu Bakr's election over the tribal chiefs and Ali . The two years of his caliphate were critical for Islam. Though he was himself fervent rather than warlike, his party crushed opposition in Arabia and began the remarkable extension of Islam as a world religion. He was succeeded by Umar.

Abu Bakr (c.573–634) First Muslim caliph (632–34). One of the earliest converts to Islam, Abu Bakr was chief adviser to the Prophet Muhammad. After Muhammad's death he was elected leader of the Muslim community. During his short reign, he defeated the tribes that revolted against Muslim rule in Medina and restored them to Islam. By invading the Byzantine Christian provinces of Syria and Palestine and the Persian province of Iraq, he launched the Holy Wars through which the first major expansion of the Islamic world was accomplished.