Immediately after Mohammad Prophet’s death, a council board al-Shura selected the caliph. Succession was therefore not hereditary. Abu Bakr was elected and the title Khalifat Rasul Allah the successor of the messenger of Allah was conferred upon aim.
With his simple and absolute faith in the new religion Abu Bakr won the title al-Siddiq, the believer. Siddiquis claim descent from him.