Oleh (Mykhail) Sviatoslavych
Oleh (Mykhail) Sviatoslavych [Svjatoslavyč], b ca 1050 [in Chernihiv?], d 6 or 24 August 1115 in Novhorod-Siverskyi. Son of Sviatoslav II Yaroslavych and father of Vsevolod Olhovych and Ihor Olhovych. After his father's death in 1076, Oleh inherited Chernihiv, but the new grand prince, Oleh's uncle Iziaslav Yaroslavych, gave Chernihiv to another uncle, Vsevolod Yaroslavych. Instead Oleh ruled Volodymyr-Volynskyi, but he was driven out in 1078 by Iziaslav and sought refuge with his brother, Roman (d 1079), in Tmutorokan. In 1078 Oleh and his cousin Borys Viacheslavych tried, with Cuman help, to regain his patrimony in Chernihiv, but they were defeated by Iziaslav and Vsevolod's army at Nezhatyna Nyva. Oleh returned to Tmutorokan, where he was captured by the Khazars in 1079 and handed over to the Byzantines. He lived in exile on Rhodes until 1083, when he returned to Tmutorokan and regained it from his cousin Davyd Ihorovych.
In 1094 Oleh took Chernihiv, after his Cuman allies had ravaged it, from his cousin Volodymyr Monomakh. He was driven out by Monomakh in 1096, fled to Starodub, and then took Murom and Rostov from Monomakh's son Iziaslav. Oleh then attacked Iziaslav's brother, Mstyslav I Volodymyrovych of Novgorod the Great, but was defeated and forced to attend the Liubech congress of princes in 1097. There Oleh forfeited Chernihiv, Murom, and Riazan but was given Novhorod-Siverskyi and the lands of Kursk (see Siversk principality), which he ruled until his death. Because of his enduring ties with the Cumans (he also married a Cuman princess) Oleh refused to join Kyivan Rus’ military expeditions against them. In the epic Slovo o polku Ihorevi and folk legends he is referred to as the Son of Grief (Horyslavych). Oleh's descendants, the Olhovych house of Chernihiv, struggled for control of the Kyivan state against the descendants of Monomakh.