pope from 824 to 827. He was a cardinal priest when chosen as successor to St. Paschal I. In 824 Eugenius received the Holy Roman co-emperor Lothar I, who had come to Rome to issue the Constitutio Romana that affirmed imperial sovereignty over Rome, demanded an oath of fealty from Eugenius, and vested papal election in the Roman clergy and nobles, subject to imperial confirmation. Despite accepting the terms, Eugenius preserved papal independence on issues of church doctrine and discipline. Eugenius opposed a revival in the Eastern Church of the Iconoclastic Controversy, a long-standing theological dispute over the worship of icons.