Upon the accession of Caliph Uthman (r. 644–656), Mu'awiya's governorship was enlarged to include Palestine, while Umayr ibn Sa'd al-Ansari was confirmed as governor of the Homs-Jazira district.^[2] In late 646 or early 647, Uthman attached the Homs-Jazira district to Mu'awiya's Syrian governorship,^[2] greatly increasing the military manpower at his disposal.^[19] The successive promotions of Abu Sufyan's sons contradicted Umar's efforts to curtail the influence of the Qurayshite aristocracy in the Muslim state in favor of the early Muslim converts.^[13] According to the historian Leone Caetani, this exceptional treatment stemmed from Umar's personal respect of the Umayyads, the branch of the Banu Abd Shams to which Mu'awiya belonged.^[14] This is doubted by the historian Wilferd Madelung, who surmises that Umar had little choice, due to the lack of a suitable alternative to Mu'awiya in Syria and the ongoing plague in the region, which precluded the deployment of commanders more preferable to Umar from Medina.^[14]