The East Slavs are a subgroup of the Slavs, who speak East Slavic languages and reside chiefly in Eastern Europe but extending also across northern Asia and the Pacific Ocean. They formed the majority of the population of the medieval state Kievan Rus', which they consider their cultural ancestor. Belarusians, Russians and Ukrainians are the existing East Slavic groups. Rusyns and Don Cossacks are sometimes considered a separate nation, though they are often considered a subgroup of Ukrainians and Russians.