Sviatoslav Olgovich (Russian and Ukrainian: Святослав Ольгович; died February 14, 1164) was Prince of Novgorod (1136–1138); Novgorod-Seversky (1139); Belgorod-Kievsky (1141–1154); and Chernigov (1154–1164). He was the son of Oleg Sviatoslavich, the prince of Chernigov, and an unnamed daughter of Aepa, a Cuman khan.[1]
After the death of their older brother, Vsevolod II, Sviatoslav and his brother Igor were driven out of Kiev by Iziaslav Mstislavich. Sviatoslav escaped, but Igor was captured and eventually killed in 1147. Sviatoslav fled to Chernigov but was ordered to relinquish his city, Novgorod-Seversky, to his cousins, Iziaslav Davidovich and Vladimir Davidovich. With the assistance of his ally, Yuri Dolgoruki, and his father-in-law, Aepa Khan, Sviatoslav began a war against his cousins, but was forced to flee to Karachev. There on January 16, 1147, Sviatoslav defeated the Davidovichi brothers.
In 1108, Sviatoslav married a Cuman princess, daughter of Aepa Khan, who gave him a daughter and a son, Oleg. In 1136 Svyatoslav married a second time, to a woman of Novgorod, who bore his famous son, Igor Sviatoslavich.