Despite numerous power struggles in Lithuania, including rebellion by Andrei of Polotsk, conquest of the Principality of Smolensk, and the Lithuanian Civil War (1389–92), Švitrigaila does not appear in politics until 1392. After the death of his mother Uliana of Tver, Jogaila appointed falconer Fedor Vesna regent of the Principality of Vitebsk. This angered Švitrigaila and he rebelled against his brother. Vytautas, who just concluded the Ostrów Agreement to become Grand Duke of Lithuania, and Skirgaila gathered an army and captured Drutsk, Orsha, and then Vitebsk. Švitrigaila was captured and sent to Kraków. He was not held in a prison as demonstrated by the fact that he headed a commission for demarcation of the Lithuanian–Prussian border in 1393, but at the same time he had no territories.