Son of the Grand Prince Volodymyr Monomakh of Kyiv and Gytha, daughter of King Harold II of England. During the lifetime of his father held the Novgorod and Pereyaslav thrones,
In 1096 defeated the army of the Prince Oleh Sviatoslavych of Chernihiv and forced him to take part in the Liubech Congress of 1097. Waged campaigns against the Polovtsians in 1093, 1107, and 1111. Carried out two successful campaigns against the Estonians in 1113 and 1116. After the death of his father (1125) he inherited the Kyivan throne and continued to enhance the prestige of the Grand Prince of Kyiv and defend the country against external enemies. Mstyslav relentlessly concerned about the strength of the country, its consolidation, and security. In 1129 he returned Polotsk under the influence of Kyiv, installing his son Iziaslav on the Polotsk throne. In 1130 fought with the Lithuanians. Routed the Polovtisans and drove them beyond the Volga and Yaik.
The immense international prestige of the Kyivan state during the reign of Mstyslav is evidenced by numerous dynastic ties of the Kyivan Prince with
Prince Mstyslav was buried in the Church of Saint Theodore Teron, which he had built in St. Theodore’s Monastery in Kyiv. After his death the Kyivan state disintegrated finally for several politically independent principalities.