Iziaslav Yaroslavych [Iz'jaslav Jaroslavyč], b 1024, d 3 October 1078. Grand prince of Kyiv intermittently from 1054 to 1078; the eldest son of Yaroslav the Wise. Before inheriting the throne of Kyiv from his father, Iziaslav Yaroslavych ruled Turiv. In the 1060s he brought most of the Rus’ territories west of the Dnieper River under his control. For refusing them arms to fight invading Cumans, the inhabitants of Kyiv revolted in 1068 (see Kyiv Uprising of 1068–9). He fled to Poland and with the aid of his brother-in-law and cousin, Bolesław II the Bold, took Kyiv a year later from Vseslav Briachislavich of Polatsk. When his brothers Sviatoslav II Yaroslavych and Vsevolod Yaroslavych of Chernihiv marched on Kyiv in 1073, its inhabitants refused to support Iziaslav Yaroslavych and he was forced to flee abroad. He sought help in 1075 from Emperor Henry IV of Germany and Pope Gregory VII, but his efforts were in vain. In 1077, after Sviatoslav II Yaroslavych, who ruled Kyiv, died and was succeeded by Vsevolod Yaroslavych, Iziaslav Yaroslavych marched on Kyiv with Polish troops. Vsevolod Yaroslavych renounced his throne and retired to Chernihiv. Iziaslav Yaroslavych died in battle helping Vsevolod Yaroslavych recapture Chernihiv from Sviatoslav II Yaroslavych's son Oleh (Mykhail) Sviatoslavych and his Cuman allies.
[This article originally appeared in the Encyclopedia of Ukraine, vol. 2 (1989).]