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.
Names and titles of Władysław II Jagiełło Jogaila, or Władysław II Jagiełło (ca.1351/1361–1434), was a Grand Duke of Lithuania and from 1386 Queen Jadwiga's husband and "jure uxoris" King of Poland. In Lithuania, he held the title "Didysis Kunigaikštis", translated as Grand Duke or Grand Prince ("kunigaikštis" is a cognate of "König" and "king", and "didysis" magnifies it).