Ethnonyms: Belarusians, Russians, Ukrainians, Rusyns / Carpatho-Rusyns
Total population: c. 210 million+
Ethnolinguistic classification: Indo-European → Slavic
Homeland: Pinsk Marshes / Pripet Marshes
Regions with significant populations: the Russian Federation, Ukraine, the Republic of Belarus
Languages and dialects: Russian, Ukrainian, Belarusian, Rusyn
Religion: Eastern Orthodoxy, the Catholic Church, the Eastern Catholic Churches; Protestantism, Judaism, Islam, atheism
Related ethnic groups: West Slavs, South Slavs, Rusyns
East Slavs are a major ethnolinguistic group centered in Eastern Europe and extending into Northern Asia, and the term chiefly refers to Russians, Ukrainians, and Belarusians; their languages are the East Slavic branch of the Slavic family—Russian, Ukrainian, and Belarusian—and they are normally written in Cyrillic, with close relatedness but also real differences in phonetics, grammar, and vocabulary. Historically, East Slavs emerged within the broader Slavic world of eastern Europe, expanded from an early homeland that Britannica places between the Elbe River and the Pripet Marshes, and were shaped by long contact with Western European, Byzantine Christian, Asian, and Middle Eastern influences; in the centuries before and after the formation of Kyivan Rus, they occupied the forest and forest-steppe zones of what are now western and north-central Ukraine and southern Belarus and later expanded farther north and northeast into territories that would become the Russian state. Their most important medieval political framework was Kyivan Rus, the first East Slavic state, which reached its peak in the early to mid-11th century; according to Britannica, Volodymyr I’s reign marked a decisive turning point when he accepted Orthodox Christianity in 988, after which the Byzantine rite spread through his domain and Old Church Slavonic became a major vehicle of literacy and worship.