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.
David of Hrodna David (Belarusian: Давыд Гарадзенскі , Lithuanian: "Dovydas Gardiniškis" , killed in 1326) was a castellan of Hrodna and one of the most famous military commanders of Gediminas, Grand Duke of Lithuania. He might have been the son of Daumantas of Pskov and great grandson of Alexander Nevsky. Maciej Stryjkowski claims that David was married to one of the daughters of Gediminas. He seems to have been a middleman between the pagan Gediminas and the Christian princes of the Rurikid family and frequently led in battle the united Lithuanian-Ruthenian armies.