As to the Slavs, who form the nucleus of the Russian population, it is now generally recognised that they migrated to Russia from the neighbourhood of the Carpathian Mountains. The Byzantine annalists of the sixth and the beginning of the seventh centuries, speaking of the Slavs, whom they called Sklaboi, a name appearing as early as the end of the fifth century, distinguish two branches of them: the Ants, living from the Danube to the mouth of the Dnieper; and the Slavs, properly so named, living northeast of the Danube and as far to the east as the source of the Vistula, and on the right bank of the Dniester. In this, their statement agrees with that of Jornandes,[l] the historian of the Goths. Some Russian scholars suppose that before coming to the Danube the Slavs lived near the Carpathians, whence they invaded the Byzantine empire. These encroachments, beginning as far back as the third century, resulted in the penetration of the Slavs into southern Austria and the Balkan peninsula. Byzantine annalists of the sixth and seventh centuries, Procopius and the emperor Maurice, who had to fight the Slavs in person, speak of them as being ever on the move: “They live in woods and on the banks of rivers, in small hamlets, and are always ready to change their abode.” At the same time these Byzantine annalists describe this people as exceedingly fond of liberty. “From the remotest period,” says Procopius,[d] “the Slavs were known to live as democracies; they discussed their wants in popular assemblies or folkmotes.” “The Slavs are fond of liberty,” writes the emperor Maurice[e]; “they cannot bear unlimited rulers, and are not easily brought to submission.” The same language is used also by the emperor Leo.[f] “The Slavs,” says he, “are a free people, strongly opposed to any subjection.” If the Byzantine historians do not speak of the invasion of the Slavs into the limits of the empire during the second part of the seventh century, it is because their migration took at this time another direction: from the Carpathians they moved toward the Vistula and the Dnieper. [Illustration: A FINNISH COSTUME] During the ninth century, the time of the founding of the first principalities, the Dnieper, with its numerous affluents on both sides, formed the limit of the Slavonic settlements to the east. This barrier was broken only by the Viatitchi, stretching as far to the northeast as the source of the Oka. On the north the Slavs reached the great Valdai plateau from which Russia’s largest rivers descend, and the southern part of the great lake region, that of Ilmen.[c]