 An Alid revolt led by Muhammad ibn Qasim broke out in Khurasan in early 834 , but was swiftly defeated and Muhammad brought as a prisoner to the Caliph 's court . He managed to escape during the night of 8 / 9 October 834 , taking advantage of the Eid al @-@ Fitr festivities , and was never heard of again . In June / July of the same year , ' Ujayf ibn ' Anbasa was sent to subdue the Zutt . These were people brought from India by the Sassanid emperors and settled in the Mesopotamian Marshes . The Zutt had rebelled against caliphal authority since ca . 820 , and had been regularly raiding the environs of Basra and Wasit since that time . ' Ujayf was successful in encircling the Zutt and forcing them to surrender after a seven @-@ month campaign , making a triumphal entry into Baghdad in January 835 with his numerous captives . Many of the Zutt were then sent to Ayn <unk> on the Byzantine frontier , where they fell fighting against the Byzantines . 
