Ishaq accordingly selected his brother Tahir to govern the shurtah in his stead and set out for the province. Upon his arrival he was able to achieve a major victory against the Khurramites, reportedly killing tens of thousands of rebels and forcing many others to flee to the Byzantines. After sending a victory dispatch in December 833, he returned to Iraq in May 834, bringing with him a large number of captives and individuals who had received guarantees of safe conduct.[12]