Principality of Chernigov
Iziaslav granted Sviatoslav's former principality to Vsevolod, but Sviatoslav's sons considered the Principality of Chernigov as their own patrimony or "otchina". Oleg Sviatoslavich made an alliance with the Cumans and invaded Chernigov. Iziaslav came to Vsevolod's rescue and they forced Oleg to retreat, but Iziaslav was murdered in the battle.