Abu Bakr — Leader
Abdullah ibn Abi Quhaafah, c. 573 CE 23 August 634 CE, popularly known by his nickname Abu Bakr, was a senior companion and the father-in-law of the Islamic prophet Muhammad. He ruled over the Rashidun Caliphate from 632 to 634 CE, when he became the first Muslim Caliph following Muhammad's death. As caliph, Abu Bakr succeeded to the political and administrative functions previously exercised by Muhammad. He was also commonly known as The Truthful... (wikipedia)