St. Peter was in Antioch, Syria (i.e., what has historically been an Orthodox area before the Muslims invaded) for 9 (nine) years before going to Rome for 2 (two) years, ending in his martyrdom. So if any Christian body in the world could lay claim to being The.True.Church.Because.of.St.Peter, it would be the Orthodox Patriarchate of Antioch.
Read more history. At the time we’re talking about, there was no “Orthodox church”. The only church in existence called itself “catholic”.