Andrei of Polotsk

Andrei of Polotsk (Belarusian: Андрэй Альгердавіч, Lithuanian: Andrius Algirdaitis, born ca. 1319 – died on 12 August 1399 in the Battle of the Vorskla River) was the eldest son Algirdas, Grand Duke of Lithuania, and his first wife Maria of Vitebsk. He was Duke of Pskov (through his deputy Yuri, 1342–1348) and Polotsk (1342–1387). As the eldest son of the Grand Duke, Andrei claimed his right to the throne after his father's death in 1377. Algirdas left Jogaila, his eldest son with his second wife Uliana of Tver, as the rightful heir. Andrei's rivalry with Jogaila, Grand Duke of Lithuania and later King of Poland, eventually led to his demise.

Read more about Andrei Of Polotsk:  Duke of Pskov and Polotsk, Struggle Against Jogaila, Capture and Release