Rostyslav Mstyslavych [Mstyslavyč], b ?, d 14 March 1167 in Zarub, on the Dnipro River. Kyivan Rus’ prince; son of Mstyslav I Volodymyrovych. He was appointed prince of Smolensk ca 1125–7 by his father. Rostyslav elevated the principality to what is regarded as its highest point of cultural development. He founded churches and towns, strengthened the fortifications of the capital, and established a separate Smolensk bishopric. After the death of his brother, Iziaslav Mstyslavych, in 1154, Rostyslav was briefly grand prince of Kyiv, which he later ruled (1159–67). During that period his diplomatic skills muted the internecine warfare in Kyivan Rus’ considerably. He died while traveling from Novgorod the Great.
[This article originally appeared in the Encyclopedia of Ukraine, vol. 4 (1993).]