Supporting Bulgaria's official Orthodox Church, Ecumenical Patriarch Bartholomew and ranking Orthodox leaders from eight nations celebrated Bulgarian Patriarch Maxim's 90th birthday at Alexander Nevski Cathedral.
Maxim has struggled to preserve church unity since 1991, when a segment of clergy seceded and sought to replace Maxim because he was appointed by the fallen communist regime, not elected by a church convention.
In the last decade, conflicts over church property have escalated to violent clashes.
Some 80 percent of Bulgarians are Orthodox, but church power struggles have disappointed many faithful and limited Orthodoxy's social role during the transition to democracy.
Bartholomew's address said the rift "will soon sink into historical oblivion."
During the birthday celebrations, President Georgi Parvanov awarded Maxim the nation's highest order, the Stara Planina.