Principality of Smolensk
Karigaila (, died on 16 September 1390 in Vilnius) was a son of Algirdas, Grand Duke of Lithuania, and his second wife Uliana of Tver. He became the ruler of Mstsislaw after he captured it from the Principality of Smolensk. He is sometimes mistaken for his brother Constantine, who was the founder of the House of Czartoryski.