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 duke 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. Polotsk was vital to Lithuanian interests as it was situated between Lithuania and the Livonian Order. Andrei became the Duke of Polotsk and helped defend Lithuania against Livonian attacks. In Pskov, Andrei left his deputy, otherwise unknown Yuri. Lithuanian historian Alvy