The area where the Orthodox Church developed encompasses a wide geographic region. Here are some of the present-day countries that fall within that region:
* Greece: Considered the historical and spiritual heartland of Orthodox Christianity.
* Turkey: The seat of the Ecumenical Patriarchate of Constantinople (Istanbul), the spiritual leader of Orthodox Christians.
* Russia: The largest Orthodox Church in terms of membership is the Russian Orthodox Church.
* Ukraine: Ukrainian Orthodox Church
* Belarus: Belarusian Orthodox Church
* Romania: Romanian Orthodox Church
* Bulgaria: Bulgarian Orthodox Church
* Serbia: Serbian Orthodox Church
* North Macedonia: Orthodox Ohrid Archbishopric
* Georgia: Georgian Orthodox Church
* Cyprus: Church of Cyprus
* Albania: Albanian Orthodox Church
* Lebanon: Significant Orthodox Christian presence.
* Syria: Significant Orthodox Christian presence.
* Israel/Palestine: Eastern Orthodox Patriarchate of Jerusalem.
* Egypt: Coptic Orthodox Church of Alexandria (though distinct, shares historical roots with the Eastern Orthodox).
This list isn't exhaustive, as Orthodoxy has spread beyond its original core regions. However, these countries represent the primary historical and present-day locations of Orthodox Christian presence and influence.