Mstyslav Danylovych [Мстислав Данилович; Danylovyč], b ?, d ca 1290–1308. Volhynian prince; son of King Danylo Romanovych. After Danylo's death he inherited Volodymyr-Volynskyi. In 1288 he succeeded his cousin, Volodymyr Vasylkovych, as prince of the Volodymyr-Volynskyi land, the Lutsk land, and the Berestia land. He took an active part in Polish conflicts and helped Konrad I of Mazovia to regain the Sandomierz land.
[This article originally appeared in the Encyclopedia of Ukraine, vol. 3 (1993).]