Abu Bakr Abdallāh bin Abi Quhafah as-Siddiq (أبو بكر عبد الله بن أبي قحافة الصديق‎‎; c. 573 - 634 CE)  was a senior companion (Sahabi) and through his daughter Aisha the father-in-law of the prophet Muhammad. He was a caliph 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. Abu Bakr's reign lasted for around 2 years ending with his death after an illness.