At the same time appeals are received at Rome from Cantacuzenos for union of western princes against Osmanlis.
1349, 1350, 1353—Cantacuzenos makes three more overtures to Clement VI and Innocent VI.
1352—Inhabitants of Philadelphia appeal to Pope for aid, promising return to Roman communion.
1363—Urban V on Holy Friday gives the cross to several princes of the Occident.
1366—Urged by Urban, Amadeo of Savoy sails for the crusade against the Osmanlis. He spends his efforts in releasing John V from the Bulgarians, and abandons the Byzantines when they refuse to return to the Roman Church. Urban writes to Louis of Hungary to put off his crusade until the union of the Churches is accomplished.
Urban V denounces the traffic of the Italian Republics with Moslems.
1369—Emperor John V, at Rome, abjures errors of Orthodox Church, and receives from Pope letters, recommending that Christian princes come to his aid.
1371—Gregory XI makes appeal to Christian nations to co-operate with Genoa in saving the last Christians of the Holy Land.
1372—Gregory urges Louis of Hungary to resist the Osmanlis before they advance farther into Europe, and orders a crusade to be preached in Hungary, Poland, and Dalmatia.
1373—Gregory, receiving the last envoy from John V, bursts into tears, and says that he will save Constantinople, if only the Byzantine Emperor will cause his people to renounce their heresies and return to the Roman Church.