14. When Michael Palaeologus, Emperor of Constantinople, in 1263 and thereafter, affirmed his desire to return in company with his Greek subjects to unity and concord with the Roman Church, Urban IV aptly proposed the condition "that in sacred ceremonies from the diptychs, the name of the Pope should be commemorated together with the four patriarchs" (Nicetas, bk. 5, chap. 2). And when thereafter the negotiation of this union was again undertaken by Emperor Michael and Patriarch Giovanni Vecco and was seriously debated at the General Council of Lyons held in the year of the Lord 1274, the Pope, Blessed Gregory X, with the agreement of the assembled council fathers, first proposed several indispensable conditions for the effective negotiation of union. The first of these was "that the Pope be included in the diptych with the other four patriarchs and commemorated during the holy services" (Nicetas, as above). And Pachymeres (bk. 5, chap. 22) testifies that this condition was accepted by the Greeks and carried out in practice: "There were two immediate results of this arrival of the ambassadors who brought back word that peace had been made on the strength of the previous agreements: the deposition of the Patriarch and the public commemoration of the Pope in holy services." 15. His son Andronicus succeeded Michael Palaeologus as emperor, and was so extreme a supporter of the schism which had been condemned that he allowed his father's body to be buried beyond the sacred precinct because he had attempted to establish a union of the Greek Church with the Latin. Because the emperor could hardly hope for success in his intended revival of the schism while the Catholic patriarch, Giovanni Vecco, was leader of the church at Constantinople, he imposed as patriarch a certain Joseph who was tainted with the stain of heresy. As a result affairs began to deteriorate and a sincere reconciliation of the churches was no longer possible. Finally, at the meeting of the General Council of Ferrara, later transferred to Florence, in the year 1434, after proper deliberations of the issues by the Greek and Latin fathers, the wall of division was cast down which had for so long kept the one church apart from the other.