The Greek diaspora, also known as Omogenia (Omogéneia), are the communities of Greeks living outside of Greece and Cyprus (excluding Northern Cyprus). Such places historically include Albania, North Macedonia, parts of the Balkans, southern Russia, Ukraine, Asia Minor, Sudan, the region of Pontus, Eastern Anatolia, Georgia, the South Caucasus, Egypt, southern Italy, and Cargèse in Corsica. The term also refers to communities established by Greek migration outside of these traditional areas; such as in Australia, Chile, Canada and the United States.
The Greek diaspora is one of the oldest diasporas in the world, with an attested presence from Homeric times to the present. Examples of its influence range from the role played by Greek expatriates in the emergence of the Renaissance, through liberation and nationalist movements involved in the fall of the Ottoman Empire, to commercial developments such as the commissioning of the world's first supertankers by shipping magnates Aristotle Onassis and Stavros Niarchos.
In Archaic Greece, the trading and colonizing activities of Greeks from the Balkans and Asia Minor propagated Greek culture, religion and language around the Mediterranean and Black Sea basins. Greek city-states were established in Southern Italy (the so-called "Magna Graecia"), northern Libya, eastern Spain, the south of France, and the Black Sea coast, and the Greeks founded over 400 colonies in these areas. Alexander the Great's conquest of the Achaemenid Empire marked the beginning of the Hellenistic period, which was characterized by a new wave of Greek colonization in Asia and Africa; the Greek ruling classes established their presence in Egypt, West Asia, and Northwest India.
Many Greeks migrated to the new Hellenistic cities founded in Alexander's wake, as geographically dispersed as Uzbekistan and Kuwait. Seleucia, Antioch and Alexandria were among the largest cities in the world during Hellenistic and Roman times. Greeks spread across the Roman Empire, and in the eastern territories the Greek language (rather than Latin) became the lingua franca.