With the attempt to resolve the “Arian” controversy, which in the 4th century CE had theologically and politically divided the church, Emperor Constantius II (r. 337–361 CE) called for two councils (Councils/Synods) to be held simultaneously in the western and the eastern parts of the Roman Empire in 358 CE. The purpose was to negotiate a theological position between Nicene and Homoian Christians, who disagreed over whether God’s being was in one or three substances (hypostaseis) of the Father, Son, and Holy Spirit, and to exclude the…