Turkey's once-flourishing Greek community is fading away. The country is predominantly Muslim and led by a secular government that's had a complicated relationship with the patriarchate.

If Turkish laws, demographics and attitudes aren't changed, Bartholomew could ultimately be the last Patriarch of Constantinople.

"We are not all in despair for the future of our church," Bartholomew said. "It is not easy, but it is not impossible."

The Turkish government can veto any candidate put forward for the position of patriarch. And it requires the patriarch be a Turkish citizen. Bartholomew is, but most of those best qualified to succeed him are not.

So the government has proposed offering Turkish citizenship to Orthodox archbishops overseas. Several have applied; so far, none has been approved.

The Turkish government also refuses to recognize the title Ecumenical Patriarch, or Bartholomew's role as an international religious leader. (NOTE: There are approx 250 million Orthodox in the world whose visible head is Patriarch Bartholomew).