A result of a gradual schism within the Roman Catholic Church, centred around the year 1054, the Orthodox Church (thats Eastern Orthodox if you want to be technical) is based in Eastern Europe.
I won't go into the belief structure, since it would require a lot of long rambling explanations of thelogical matters and differences with Rome so I'll just link to this: http://en.wikipedia.org/wiki/Eastern_Orthodox_Christian_theology
Right now, the Orthodox Church is nearly entirely insode the Ottoman Empire. It is dominated by the larger Muslim church. The Otts tolerate the Orthodox Church (they do beleive in Jesus as a prophet after all) but view them with a degree of suspecion.
The church's head is Jesus Christ. Next is the Patriarch of Constantinople (not the equivelant of the Pope) who in 1529 is Jeremias I.
Party of Five, a brilliant show, and often made me cry uncontrollably, suffered ultimately from a lack of rocket launchers.
- Joss Whedon
Never take life seriously. Nobody gets out alive anyway.