Principality of Halych
Following the death of Yaroslav Osmomysl on 1 October 1187, trouble began in the Principality of Halych, due to the strife between his two sons, Oleg and Vladimir. Roman urged the Galicians to evict Vladimir and make himself their prince, but they failed to either expel or kill Vladimir. However, when the Galicians threatened to kill his wife, Vladimir took her and fled to King Béla III of Hungary (1172–1196). According to a late chronicle, Oleg was appointed by Duke Casimir II of Poland (1177–1194) to rule the Principality of Halych, but the Galicians poisoned him and invited Roman to be their prince. When accepting their offer, Roman gave his patrimony of Vladimir-in-Volhynia to his brother, Vsevolod Mstislavich.