Anatolius, Constantinopolitan

Anatolius (d. 458) was patriarch of Constantinople from 449 to 458 and a central figure in the Christological controversies that defined the fifth-century church. Originally a deacon under the controversial patriarch Dioscorus of Alexandria, Anatolius shifted his allegiance to accept Pope Leo's Tome and the Chalcedonian definition — a pragmatic move that Leo never fully trusted. He appears 12 times in this collection as a recipient of Leo's letters, and the correspondence reveals a pope who was simultaneously relieved to have Constantinople's support and suspicious of Anatolius's motives. Leo wrote to Anatolius about doctrinal compliance, jurisdictional disputes (particularly Canon 28 of Chalcedon, which elevated Constantinople's status), and the ongoing implementation of the Chalcedonian settlement. The Leo-Anatolius correspondence matters because it documents the emerging rivalry between Rome and Constantinople — two sees that needed each other but could not agree on their relative status. The tensions visible in these letters would, over the centuries, contribute to the Great Schism of 1054.