Born to Abu Quhafa and Umm al-Khayr of the Banu Taym, Abu Bakr was amongst the earliest converts to Islam and propagated the faith via dawah, as a result of which many later companions converted. He was known to have freed slaves, including Bilal ibn Rabah. He suffered persecution by the Mushrikites and later accompanied Muhammad on his migration to Medina. As a member of Muhammad's haras, Abu Bakr participated in Muhammad's expeditions against the Mushrikites. He was appointed amir al-hajj by Muhammad and served as the latter's deputy. In the absence of Muhammad, Abu Bakr led the prayers and expeditions.
Following Muhammad's death in 632, Abu Bakr succeeded the leadership of the Muslim community as the first caliph, being elected at Saqifa. His election was contested by a number of rebellious tribal leaders. During his reign, he overcame a number of uprisings, collectively known as the Ridda Wars, as a result of which he was able to consolidate and expand the rule of the Muslim state over the entire Arabian Peninsula. He also commanded the initial incursions into the neighbouring Sassanian and Byzantine empires, which in the years following his death, would eventually result in the Muslim conquests of Persia and the Levant. Apart from politics, Abu Bakr is also credited for the compilation of the Quran, of which he had a personal caliphal codex. Prior to dying in August 634, Abu Bakr nominated Umar (r. 634-644) as his successor. Along with Muhammad, Abu Bakr is buried in the Green Dome at the Al-Masjid an-Nabawi in Medina, the second holiest site in Islam. He died of illness after a reign of 2 years, 2 months and 14 days, the only Rashidun caliph to die of natural causes.
Though Abu Bakr's reign was short, it included successful invasions of the two most powerful empires of the time, a remarkable achievement in its own right. He set in motion a historical trajectory that in a few decades would lead to one of the largest empires in history. His victory over the local rebel Arab forces is a significant part of Islamic history. In Sunni Islam, Abu Bakr is considered the first of the rightly-guided caliphs and the greatest after the prophets. Shia tradition considers Abu Bakr an usurper of the caliphate and an enemy of the ahl al-bayt.