Al Mu’tasim’s armies were among the strongest ever fielded by the caliphate. They reliably triumphed over their foes and faced no problems putting down any resistance to the caliph’s authority. Al Afshin and the Ushrusania were some of their most important elements, responsible for some of the umma’s most celebrated victories. Their reputation took a nosedive in the last few years of the caliph’s reign after al Afshin’s ambition got the best of him.