Vladimir Olgerdovich was a son of which ruler of medieval Lithuania?
Algirdas Algirdas (Belarusian: Альгерд , Russian: Ольгерд , Polish: "Olgierd" ;  1296  – May 1377) was a ruler of medieval Lithuania. He ruled the Lithuanians and Ruthenians from 1345 to 1377. With the help of his brother Kęstutis (who defended the western border of the Duchy) he created an empire stretching from the present Baltic states to the Black Sea and to within fifty miles of Moscow.
Sophia of Halshany Sophia of Halshany or Sonka Olshanskaya (Belarusian: Соф'я Гальшанская, "Sofja Halšanskaja" ; Lithuanian: "Sofija Alšėniškė" ; Polish: "Zofia Holszańska" ;  1405 – September 21, 1461 in Kraków) was a Grand Duchy of Lithuania princess of Halshany. As the fourth and last wife of Jogaila, King of Poland and Supreme Duke of Lithuania, she was Queen consort of Poland (1422–1434). As the mother of Władysław III, King of Poland and Hungary, and Casimir IV, Grand Duke of Lithuania and King of Poland, she was the founder of the Jagiellon dynasty.