Andrei of Polotsk
Andrei of Polotsk (, , , ca. 1325 – 12 August 1399, in the Battle of the Vorskla River) was the eldest son of Algirdas, Grand Duke of Lithuania, and his first wife Maria of Vitebsk. He was the Prince 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. Prince of Pskov and Polotsk In 1342, Andrei joined his father Algirdas and uncle Kęstutis in a war against the Livonian Order to help the Pskov Republic. The Republic asked him to stay as a prince of Pskov so that his presence would guarantee continuous support from Algirdas. Andrei accepted and was baptized in Orthodox rite (his pagan name is unknown). However, he stayed there for a very short time and returned to Lithuania. Reasons are not entirely clear, but historians speculate it was related to death of his great-uncle Vainius, Duke of Polotsk.