Greek East and Latin West

The terms "Greek East" and "Latin West" originally distinguished the Greco-Roman world between the Greek-dominated Eastern Mediterranean and the Latin-dominated Western Mediterranean. These diverging identities effectively bisected the Roman Empire into cultural and linguistic halves—the Eastern Empire (or Byzantine) and the Western Empire—and later defined the dynamic of medieval Christianity in relation to the East–West Schism, which affected Christendom across Europe, West Asia, and North Africa after AD 1054.

Source: Wikipedia — Greek East and Latin West (CC BY-SA 4.0)