Date of birth unknown; died 1205. Prince of Novgorod in 1168 and 1169, prince of Vladimir-Vo-lyn from 1170 to 1205, and prince of Galich from 1199 to 1205. Son of Mstislav Iziaslavich, the grand prince of Kiev, and of the daughter of King Bolesiaw the Wry-mouthed of Poland.
Roman Mstislavich was successful in his struggle against the boyars and the church elite to strengthen the authority of the prince. He ruled over the unified Galician-Volynian Principality and later extended his authority to Kievan territory, thus becoming one of the most powerful princes of Rus’. His policies attracted the attention of Byzantium, Poland, and Hungary. Pope Innocent III offered to crown Roman king if the latter accepted Catholicism, but the proposal was rejected. Roman took part in the internecine struggle of the Polish princes in an attempt to increase his influence in Polish affairs and expand his power into Saxony. He was killed in 1205, when he was ambushed by the Poles on the Vistula, near Zawichost.