Nationalism as ideology in modern Greece answered a challenging task: establish the link between Modern and Ancient Greece and by so doing create a definite relationship with the Western democracies, heirs of the Athenian polis of the 5th century BC. This article looks into this process by analysing the use of two fundamental terms in contemporary Greek: genos and ethnos. Genos, (from the verb gignomai, to be born, to become), a key word within a patrilineal -and Mediterranean- kinship system, stands as the equivalent of "nation" in Ottoman times, when genos referred to the Rum millet, the greek-orthodox religious minority, a category involving both kinship and religious ties. Ethnos takes over from genos during the 19th century, as notions of territory, citizenship and state authority become constitutive of collective identity. Hence self-representations opposing Balkan=traditional to European=modern social and cultural systems inform contemporary conflicts involving ethnic identity in the Balkans.