The «Caliph of the Messenger» was the first caliph of the Muslim Empire. Abu Bakr was a central companion of the Prophet PBUH early in his messenger-ship. He also was the key figure in uniting the Arabian peninsula during the Apostate wars, bringing the civil war to an end, focusing on internal improvements while also simultaneously engaging the Roman and Persian Empires. By Syrian scholar Abd al-Sattar al-Shaykh (b. 1955).