Passage: The Varangians later assimilated into the Slavic population and became part of the first Rus' dynasty, the Rurik Dynasty. Kievan Rus' was composed of several principalities ruled by the interrelated Rurikid knyazes ("princes"), who often fought each other for possession of Kiev.The Golden Age of Kievan Rus' began with the reign of Vladimir the Great (980–1015), who turned Rus' toward Byzantine Christianity. During the reign of his son, Yaroslav the Wise (1019–1054), Kievan Rus' reached the zenith of its cultural development and military power. The state soon fragmented as the relative importance of regional powers rose again. After a final resurgence under the rule of Vladimir II Monomakh (1113–1125) and his son Mstislav (1125–1132), Kievan Rus' finally disintegrated into separate principalities following Mstislav's death.The 13th-century Mongol invasion devastated Kievan Rus'. Kiev was totally destroyed in 1240. On today's Ukrainian territory, the principalities of Halych and Volodymyr-Volynskyi arose, and were merged into the state of Galicia-Volhynia.Danylo Romanovych (Daniel I of Galicia or Danylo Halytskyi) son of Roman Mstyslavych, re-united all of south-western Rus', including Volhynia, Galicia and Rus' ancient capital of Kiev. Danylo was crowned by the papal archbishop in Dorohychyn 1253 as the first King of all Rus'. Under Danylo's reign, the Kingdom of Galicia–Volhynia was one of the most powerful states in east central Europe.

Question: Where did the Varangians assimilate to?
Slavic population