Oleg Yaroslavich

Oleg Yaroslavich, called Nastasich (died 1188), was the illegitimate son of the Halych prince Yaroslav Osmomysl by his mistress Anastasia Charg. In 1170 Yaroslav put aside his wife Olga, who fled with her son Vladimir, while Yaroslav favored Oleg.

In 1187 he left Halych to Oleg, giving Vladimir only Peremyshl, but the boyars drove Oleg out. He fled to Rurik Rostislavich, then joined the Polish king Casimir II, who restored him in Halych. Oleg was soon poisoned, and the boyars invited Roman Mstislavich.