 In the third week of July 632, the Caliph Abu Bakr scraped together an army mainly from the Banu Hashim (the clan of Muhammad) to defend Medina from an imminent invasion by the apostate forces of Tulayha, a self-proclaimed prophet.The army included stalwarts like Zubayr, and Talha ibn Ubaidullah.Each of them was appointed as commander of one-third of the newly organised force.