The nomadic peoples of the Northwestern Black Sea region had a part in the ethnogenesis of the east Slavs. These Scythian and Sarmatian Iranian-speaking tribes played a big part in the original ethno-genesis of the East Slavs. This influence manifested itself in the material and spiritual culture and in the language. The Slavic-Iranian symbiosis of the East Slavs resulted in a distinction of the East Slavs from the rest of the Slavic World. The name of the tribal union - Antes - the ancestors of the East Slavs, demonstrated Iranian ancestry. Uliches, Tivertsy and Chorvats, tribes of Antes, were the basis of the formation of the Rusin ethnos. The long period of interactions with the nomadic world also led to the formation of a specific economic structure among the Rusins where agriculture combined with cattle raising. The name of the tribe "Chorvaty" in translation from Iranian means "guard of cattle".