The Greeks, also known as the Hellenes (Greek: Ἕλληνες, [ˈelines]), are an ethnic group native to Greece, Cyprus and other regions. They also form a significant diaspora, with Greek communities established around the world. Greek colonies and communities have been historically established in most corners of the Mediterranean, but Greeks have always been centered around the Aegean Sea, where the Greek language has been spoken since antiquity. Until the early 20th century, Greeks were uniformly distributed between the Greek peninsula, the western coast of Asia Minor, Pontus, Egypt, Cyprus and Constantinople; many of these regions coincided to a large extent with the borders of the Byzantine Empire of the late 11th century and the Eastern Mediterranean areas of the ancient Greek colonization. In the aftermath of the Greco-Turkish War (1919–1922), a large-scale population exchange between Greece and Turkey transferred and confined Christians from Turkey, except Constantinople (effectively ethnic Greeks) into the borders of the modern Greek state and Cyprus. Other ethnic Greek populations can be found from southern Italy to the Caucasus and in diaspora communities in a number of other countries. Today, most Greeks are officially registered as members of the Greek Orthodox Church.