Arguably the first Christian Slavs were the Croats (and soon afterwards the Serbs) who accepted baptism, having become allies of Emperor Heraclius (r. īeginning in the 7th century, the Slavs gradually converted to Christianity (both Byzantine Orthodoxy and Roman Catholicism). The Slavs' original habitation is still a matter of controversy, but scholars believe that it was somewhere in Eastern Europe. Over the next two centuries, the Slavs expanded southwest toward the Balkans and the Alps and northeast towards the Volga River. By then, the nomadic Iranian ethnic groups living on the Eurasian Steppe (the Scythians, Sarmatians, Alans etc.) had been absorbed by the region's Slavic population.
The first written use of the name 'Slavs' dates to the 6th century, when the Slavic tribes inhabited a large portion of Central and Eastern Europe. The early Slavs were a diverse group of tribal societies who lived during the Migration Period and the Early Middle Ages (approximately the 5th to the 10th centuries) in Central and Eastern Europe and established the foundations for the Slavic nations through the Slavic states of the High Middle Ages.
Battle between the Slavs and the Scythians - painting by Viktor Vasnetsov (1881).
