CAIRO (AP) — The spiritual seat of the world’s Orthodox Christians on Friday issued a call for unity ahead of the first ever meeting of the faith’s 14 independent churches that is expected to discuss the churches’ common future and efforts to heal the nearly 1,000- year rift with the Roman Catholics.

The meeting later this month in Crete will be convened by Ecumenical Patriarch Bartholomew I, the Istanbul-based spiritual leader of the world’s 300 million Orthodox Christians.

All the Orthodox churches, old and new that emerged over the centuries, have never met like this before – not since the “great schism” of 1054, when the Orthodox and Roman Catholics split after disputes over the Vatican’s power.

Preparations for the meeting have been underway since 1961, when the planning first began.