Suzdal Rus, or the duchy of Vladimir-Suzdal, was located between middle and lower Oka river on the one side, and upper and middle Volga on the other side, along rivers Klyazma and Moskva, tributaries of Volga. Places located northwards from middle Volga, along rivers Sheksna and Kostroma, always tended to have close links with Suzdal Rus. This area was primarily inhabited by Finno-Ugrian tribes of merya and muroma. Weakness of these tribes permitted the Slavs from upper Dnieper and Volga to enter their country and establish their colonies there. On the dawn of Russian history, there was a Slavs' settlement on lake Belo-ozero, which belonged to Novgorod. Cities Rostov and Suzdal, founded by settlers from Novgorod, are also very old, it seems. To the south from these cities, on river Oka, there was another town, Murom, founded in the times of Vladimir Monomakh, or even earlier. At the same time, town Vladimir was founded on river Klyazma. In the times of Yaroslav the Wise town Yaroslavl was founded on Volga. Till the end of XI century, all this north-eastern part of Rus was a distant secluded land, in the deep forests of which a few Finnish villages were scattered. Merya and muroma did not build towns, and didn't form a political entity. Their only rulers were shamans, called volkhvy (singular volkhv)by Slavs.
In the end of XI century, after the Lyubech congress of 1097, the area around Suzdal became a separate duchy. The knyazes agreed to give it to Vladimir Monomakh. After that, the growth of Russian towns began. Monomakh himself, his son Yuri Dolgorukiy and grandsons Andrei Bogolyubski and Vsevolod the Big Nest made Suzdal Rus a flourishing land in the course of one century. Knyaz Yuri built Moscow and Yuryev, Andrei built Bogolyubovo. At about the same time other cities appeared: Tver, Kostroma, Galich "Merski" ("in the land of merya"), etc. By building new towns, roads, fords and bridges, knyazes facilitated immigration. People went there from the western lands — Novgorod, Polotsk, Smolensk — from the southern lands of Vyatiches and even from Kiev. The migration from Novgorod and Smolensk was constant, it began in the earliest times and never ceased since then.
Migration from the south began later. The southern duchies, lying on Dnieper, were separated from Suzdal lands by impassable forests in the land of Vyatiches, which obstructed the communication between Kiev and Suzdal. In the earlier centuries, travellers had to go round along Volga. In the XII century, new roads appeared connecting Dnieper and Oka. Immediately, people started moving northwards from Kievan Rus, for the reasons we already know: knyazes' feuds, Polovtsians' raids, poverty. People attempted to hide in the deep forests, then crossed them and finally arrived to the Suzdal land, which they called Zalesye (land behind the forests). The southerners gave habitual names to the places. In the south, there were towns Pereyaslavl on river Trubezh, Starodub, Galich, Zvenigorod. Now, in the north they built two Pereyaslavls located on rivers both named Trubezh. Two Starodubs appeared, Ryapolovski and Okski. New cities were called Galich Merski (from merya) and Zvenigorod. The southerners also brought their folklore, the songs about Kievan knyazes and their wars with the steppe nomads. The flow of southerners strengthened the positions of Russians and assisted the rise of these lands.
Under the pressure of this migration, the Finnish tribes either left their lands, or were assimilated, losing their language and even appearance. The chronicler, who mentions merya in the first chapters of his book, seems to forget about them later. If they left their lands or were killed, the chronicle would have mentioned these cases. But since merya were gradually and peacefully assimilated, the event passed unnoticed. But this assimilation had certain consequences for the Russian population. They acquired new physical and psychological features of their new kin. Their Slavic features changed and a new Slavic people was formed. This people which included Russian Slavs from various regions of Rus and an admixture of Finns, became known as great Russians.