Greek communities in Azov area, nowadays region of Donetsk in South Ukraine, were established by Greek settlers, coming from Crimean peninsula. In 1778, six years before Catherine the Great finally took Crimea from the Ottoman Empire, 18,000 Crimean Greeks, along with other Christians, mostly Armenians, living under Tatar rule, successfully petitioned the empress for permission to move to Russia and emigrated to the shores of the sea of Azov, where they founded the city of Mariupol and several villages. At the same time the migrants obtained administrative and religious autonomy. The decision for migration of Greeks from Crimea was part of a colonization plan of the newly conquered lands of Novorossia (South Ukraine) at the end of 18th century, led by Prince Grigory Potemkin, who was granted absolute rule over the area by Catherine the Great. In addition, the exodus of all Christians (Greeks, Armenians, Vlachs, and Georgians) from Crimea helped Russia to annex the Crimean Khanate five years later, in 1783.
Speaking of Greeks of Mariupol we have to bear in mind that this term unites the two following entities: the Roomies (Rumaioi), whose language is divided into five dialects referred to the Greek, and the Aurums (Urum), who speak four dialects of the Tartaric language. They both call themselves Greeks, mainly because of their confessional adherence to Orthodoxy, as the religion confession, since the 13th century, was the dominant criterion that had separated this part of population from the Muslim majority, in the Tartar Khanate. Moreover, in Crimea as supreme leader of Christians was recognized the Patriarch, who was designated Roum millet-bashi. Roum millet included all Orthodox Christians under Ottoman rule, regardless of their nationality in the modern sense.