 Complete the following phrase:  He first appears in written sources as a witness to the Pact of Vilnius of January 1401. His patrimony was in Deltuva, but he also had possessions in Samogitia and volost of Svislach. In 1409, he became Elder of Samogitia and instigated the Second Samogitian Uprising on orders of Vytautas, Grand Duke of Lithuania. The uprising grew into the 