The clerics must confront a bigger quandary that has been growing for decades: how to balance between Israeli and Palestinian demands and maintain their delicate role as the historical caretakers of Christianity in the Holy Land.
''In this sense, it is an event of significance for the whole Christian world," said Alexander Belopopsky, a spokesman for the Geneva-based World Council of Churches, an inter-religious group that includes the more than a dozen Orthodox churches.
The Orthodox patriarchate in Jerusalem, dominated by Greeks since antiquity, is under pressure from many sides.
There are demands for greater external scrutiny into church finances and its vast land holdings. Israelis worry the church has become too pro-Palestinian. But Orthodox clerics face an undeniable fact: Palestinian Christians are the bulk of their 100,000-member flock and are pressing for more say in church affairs.
''The church cannot ignore the Arabization of the patriarchate," said the Rev. Peter Herrs, a theologian based in Greece. ''To continue with a purely Greek leadership is considered wrong in many eyes."
The Istanbul proceedings are the first major pan-Orthodox summit in more than a decade. The gathering has no authority to formally dismiss Irineos or pick his successor. That duty rests solely with the synod, or governing council, of the Jerusalem church. And Irineos refuses to convene the synod.
But leading clerics from across the Orthodox world may use the Istanbul meeting to further isolate Irineos and voice opinions about how to regain the church's credibility after months of upheaval in Jerusalem.
A former financial adviser to Irineos is accused of giving Jewish investors 198-year leases for two church-owned hostels and several shops in the Old City. Palestinians were outraged, contending the deals were part of Jewish encroachment into Arab quarters.
