Died in 1399

Feb 3 John of Gaunt 1st Duke of Lancaster a member of the House of Plantagenet, the third surviving son of King Edward III of England and Philippa of Hainault. He was called "John of Gaunt" because he was born in Ghent, then rendered in English as Gaunt. When he became unpopular later in life, scurrilous rumours and lampoons circulated that he was actually the son of a Ghent butcher, perhaps because Edward III was not present at the birth. This story always drove him to fury
Mar 18 Jelena Gruba Queen of Bosnia from 1391 to 1398, first as queen consort until 1395 and then as queen regnant. She was the only female head of state in the history of Bosnia and Herzegovina. Born into the Nikolić noble family, which ruled a part of Zachlumia, she was the wife, widow and elected successor of Stephen Dabiša, a member of the House of Kotromanić
Apr 6 Christian V Count of Oldenburg the ruling count of Oldenburg from 1368 until 1398. He was born sometime before 1347 to Count Conrad I of Oldenburg and Ingeborg of Brunswick. After his father died in 1368, he ruled Oldenburg jointly with his elder brother Conrad II, and after Conrad II's deaths in 1386, with the latter's son, Maurice II
Jul 13 Peter Parler a German architect, best known for building Saint Vitus Cathedral and Charles Bridge in Prague, where he lived from about 1356.
Jul 17 Jadwiga of Poland queen of Poland from 1384 to her death. She was a member of the Capetian House of Anjou, the daughter of king Louis I of Hungary and Elizabeth of Bosnia
Aug 12 Spytek of Melsztyn (died 1399) a Polish nobleman.
Aug 12 Andrei of Polotsk the eldest son of Algirdas, Grand Duke of Lithuania, and his first wife Maria of Vitebsk. He was Duke of Pskov and Polotsk. As the eldest son of the Grand Duke, Andrei claimed his right to the throne after his father's death in 1377. Algirdas left Jogaila, his eldest son with his second wife Uliana of Tver, as the rightful heir. Andrei's rivalry with Jogaila, Grand Duke of Lithuania and later King of Poland, eventually led to his demise
Aug 26 Mikhail II of Tver Grand Prince of Tver and briefly held the title of Grand Prince of Vladimir. He was one of only two Tver princes after 1317 to hold the grand princely title, which was almost the exclusive purview of the Muscovite princes
Sep 22 Thomas de Mowbray 1st Duke of Norfolk an English peer. As a result of his involvement in the power struggles which led up to the fall of Richard II, he was banished and died in exile in Venice
Oct 5 Raymond of Capua a leading member of the Dominican Order and served as its Master General from 1380 until his death. He was beatified by the Catholic Church in 1899. First as Prior Provincial of Lombardy and then as Master General of the Order, Raymond undertook the restoration of Dominican religious life. For his success in this endeavor, he is referred to as its "second founder"
Nov 1 John V Duke of Brittany Duke of Brittany and Count of Montfort from 1345 until his death and 7th Earl of Richmond from 1372 until his death.