Emperor Justinian reigned from 527 to 565, but had already played a decisive role in the reign of his uncle and predecessor Justin I (r. 518–527). Before Justin, imperial policy in Christological matters was officially dictated by the Henotikon that had been issued in 482 to reconcile pro- and anti-Chalcedonian factions within the church. Written by the patriarch Acacius of Constantinople and promulgated by Emperor Zeno, this document embraced a studied ambiguity by avoiding technical terminology in minimalist Christological formulations, by giving approval to both aspects of Cyril’s theology (represented by the strongly miaphysite Twelve Chapters and the dyophysite-leaning Letter of Reunion to John of Antioch), and by reducing the council’s work to the condemnation of Nestorius and Eutyches in order to undermine the achievement of the Chalcedonian Definition. Western bishops, who held Chalcedon in high regard, rejected the Henotikon outright, leading the bishop of Rome to break off communion with Acacius, resulting in the so-called Acacian Schism.