This chapter begins with John’s potential relations with maverick bishop, the official cofounder of the Sasanian Christian Church, Marouta of Maiferqat. To understand this founding that took place roughly between 410 and 424, one needs to explore for context the fascinating story of how the Sasanian state pioneered state religious policies originally for their emphasis on Mazdaism but later for dealing with other growing religions and especially Christianity. Subsequent reactions of Theodosius II’s (reigned 408—450) court to Sasanian policy as well as diplomacy with peoples on the border will round out the picture. Marouta in turn became instrumental in the development of a distinct Sasanian Christian church. Marouta, living on the border with Persia, speaking daily with Syriac Christians many of whose loyalties extended to the Syriac Catholicos of Seleucia, would certainly have become familiar with the Christian view of Sasanian policy.