Abu Bakr رضي الله عنه was the first caliph of Muslims. His name was Abdullah ibn abi qahafa. He was also the father in law of the Prophet Muhammad صلى الله عليه وسلم. He was the first adult man to embrace Islam. After he embraced Islam, many people embraced Islam as a result of his conversion since he was a known personality of Makkah and people knew him for his good character. Amongst these people who converted to Islam because of him were Zubair, Uthman, Talha and Saad ibn abi waqas. Similarly he also freed many Muslim slaves from their unbeliever and cruel masters, amongst them was Bilal as well. He remained with the Prophet Muhammad صلى الله عليه وسلم for 22 years, till his death. He had also the honor of being the companion of Prophet Muhammad صلى الله عليه وسلم when he migrated from Makkah to Madinah. He remained in the Jabal Thowr for three days with the Prophet صلى الله عليه وسلم during which his children would bring food for them, and inform them of the plannings of the kuffar of Makkah.