John XIX played a role in the process leading to the Schism of 1054 by rejecting a proposal by Patriarch Eustathius of Constantinople to recognise that patriarchate's sphere of interest in the east.Previté-Orton, p. 275. Against the grain of ecclesiastical history, John XIX agreed, upon being paid a large bribe, to recognize the patriarch of Constantinople's claim to the title of ecumenical bishop. However, this proposal excited general indignation throughout the Church, compelling him almost immediately to withdraw from the agreement.
