 Complete the following phrase:  The Treaty of Lyck was a treaty between Vytautas the Great, future Grand Duke of Lithuania, and the Teutonic Knights, represented by Marquard von Salzbach, komtur Arnold von Bürglen, and Thomas, son of Lithuanian duke Survila. It was signed on 19 January 1390 in Lyck, State of the Teutonic Order, now Ełk, Poland. Vytautas, in exchange for a military alliance against his cousin Jogaila during the 