The article discusses the historical role of ethnic migrations and formation of diaspora groups as a factor of unity North-Western Black sea with the whole Mediterranean-black sea region, in particular, a special role of the Pontic cultural world in the unity of the Mediterranean-black sea region, as well as the influence of Roman classical culture in the Moldovan culture and communications of Moldova with modern Italy. Examples of traces of ancient cultures formed as a result of powerful migrations and interaction of local and alien ethnic groups are given in the language, toponyms, architectural monuments, etc. The article also examines the historical role of the Armenian diaspora, which historically also connected the shores of the Mediterranean and Black seas (Great Armenia I in BC - II century ad, Cilician Armenia, Byzantine Armenia). As an example of a great personality who linked the political interests of Moldova, Turkey and Russia, the activities of the diplomat Manuk Bey Mirzayan are cited.