Proto-Slavs

The early Slavs were a diverse group of tribal societies who lived during the Migration Period and Early Middle Ages (approximately the fifth to the tenth centuries) in Eastern Europe and in Central Europe and established the foundations for the Slavic nations through the Slavic states of the High Middle Ages. The first written use of the name "Slavs" dates to the sixth century, when the Slavic tribes inhabited a large portion of Central and Eastern Europe. By that century, native Iranian ethnic groups (the Scythians, Sarmatians, and Alans) had been absorbed by the region's Slavic population. Over the next two centuries, the Slavs expanded southwest toward the Balkans and the Alps and northeast towards the Volga River.

Beginning in the ninth century, the Slavs gradually converted to Christianity (both Byzantine Orthodoxy and Roman Catholicism). By the 12th century, they were the core population of a number of medieval Christian states: the East Slavs in Kievan Rus', the South Slavs in Bulgaria, Croatia, Bosnia and Serbia and the West Slavs in Poland, the Holy Roman Empire (Pomerania, Bohemia, Moravia) and the Kingdom of Hungary (Nitria).