What is the name of the Baltic tribe duke known as King Vester?
Semigallians Semigallians (Latvian "Zemgaļi"; Lithuanian: "Žiemgaliai" , also Zemgalians, Semigalls, Semigalians) were the Baltic tribe that lived in the southcentral part of contemporary Latvia and northern Lithuania. They are noted for their long resistance (1219–1290) against the German crusaders and Teutonic Knights during the Northern Crusades.
Names and titles of Władysław II Jagiełło Jogaila, or Władysław II Jagiełło (ca.1351/1361–1434), was a Grand Duke of Lithuania and from 1386 Queen Jadwiga's husband and "jure uxoris" King of Poland. In Lithuania, he held the title "Didysis Kunigaikštis", translated as Grand Duke or Grand Prince ("kunigaikštis" is a cognate of "König" and "king", and "didysis" magnifies it).