The Great Schism happened in the 11th century and so, this city was the center of the EASTERN ORTHODOX CHURCH ( and still is, by the way), NOT THE ROMAN CATHOLIC CHURCH.
Since the head of your church is the POPE in Roman not the Patriarch of Constaninople, you are not Eastern Orthodox and not even in Communion with them!
I could type a whole bunch but it has already been done for me. There is a good explanation here:
http://byzcath.org/Faith-and-Worship/Who-Are-Byzantine-Catholics.htm