 The number of Christian elites in the bureaucracy increased, a flow which continued until the fall of the empire in 651.Although priestly leaders such as Shemon Bar Sabbae and his colleagues had zealously opposed Shapur II's request to participate in the imperial bureaucracy, the bishops began operating as agents of Iran (dissociating themselves from Zoroastrianism) during the fifth century.Yazdegerd made use of the priestly leaders, sending the Patriarch of the Catholicos of Ctesiphon to mediate between himself and his brother (the governor of Pars, in southern Iran).