Alexander Vygantas was the duke of which city in Lithuania?
Vygantas Vygantas (baptized Alexander; Polish: "Wigunt" ; died June 28, 1392) was Duke of Kernavė. He was one of the sons of Algirdas, Grand Duke of Lithuania (1345–1377), and his second wife Uliana Alexandrovna of Tver.
Friedeburgh Friedeburgh or Friedeburg was a short-lived castle of the Teutonic Order in Samogitia (exact location is unknown). It was built after the Treaty of Salynas was signed in 1398 and Samogitia was granted to the Knights by Vytautas, Grand Duke of Lithuania. The castle was to become administrative center of Samogitia.