Volodymyr-Volynskyi principality. A principality of medieval Kyivan Rus’, covering the upper and middle reaches of the Buh River and the tributaries of the Prypiat River. It was formed in the 10th century out of territories inhabited by the Volhynians. Vsevolod, the son of Volodymyr the Great, was its first ruler. The Liubech congress of princes in 1097 awarded the principality to Davyd Ihorovych, and the Vytychiv congress of princes in 1100 overturned that decision in favor of Sviatopolk II Iziaslavych. Volodymyr Monomakh seized the territory and placed it under his son, Andrii (1118–34). Then it was ruled by Iziaslav Mstyslavych for two decades (1134–54). After his death the principality was divided among his sons, and became independent of Kyiv. Volodymyr-Volynskyi principality reached its apex under Roman Mstyslavych (1170–1205), who strengthened the power of the prince over the boyars and merged the principality with Halych principality in 1199, thereby creating the Principality of Galicia-Volhynia.
[This article originally appeared in the Encyclopedia of Ukraine, vol. 5 (1993).]