Ridda wars
Muhammad died in June 632, and Abu Bakr was appointed Caliph and political successor at Medina. Soon after Abu Bakr's succession, several Arab tribes revolted against him in the "Ridda wars" (Arabic for the Wars of Apostasy). The Campaign of the Apostasy was fought and completed during the eleventh year of the Hijri. The year 12 Hijri dawned, on 18 March 633, with Arabia united under the central authority of the Caliph at Medina.