Vygantas was Duke of Kernavė

Kernave

Kernavė was a medieval capital of the Grand Duchy of Lithuania and today is a tourist attraction and an archeological site . It is located in the Širvintos district municipality located in southeast Lithuania...

. He was one of the sons of Algirdas

Algirdas

Algirdas was a monarch of medieval Lithuania. Algirdas ruled the Grand Duchy of Lithuania from 1345 to 1377, which chiefly meant monarch of Lithuanians and Ruthenians...

, Grand Duke of Lithuania (1345–1377), and his second wife Uliana Alexandrovna of Tver

Uliana Alexandrovna of Tver

Uliana Alexandrovna of Tver was a daughter of Grand Prince Alexander of Tver and Anastasia of Halych, and second wife of Grand Prince of Lithuania Algirdas. After the death of her husband Uliana became a nun under the name Marina...

.

In 1385 Vygantas supported his older brother Jogaila

Jogaila

Jogaila, later 'He is known under a number of names: ; ; . See also: Jogaila : names and titles. was Grand Duke of Lithuania , king consort of Kingdom of Poland , and sole King of Poland . He ruled in Lithuania from 1377, at first with his uncle Kęstutis...

 by signing the Union of Krewo

Union of Krewo

In a strict sense, the Union of Krewo or Act of Krėva was a set of prenuptial promises made in the Kreva Castle on 14 August 1385 by Jogaila, Grand Duke of Lithuania, in exchange for marriage to the underage reigning Queen Jadwiga of Poland...

. In 1386 he was baptized as Alexander and married with Hedwig, daughter of Władysław Opolczyk, in 1390. Polish nobles expected that Władysław would grant Vygantas the Dobrzyń Land

Dobrzyn Land

Dobrzyń Land is a historic region around the town of Dobrzyń nad Wisłą in Poland, east of the Vistula River and south of the Drwęca, where it borders on the Kulmerland...

, contested territory between Poland and the Teutonic Knights

Teutonic Knights

The Order of Brothers of the German House of Saint Mary in Jerusalem , commonly the Teutonic Order , is a German medieval military order, in modern times a purely religious Catholic order...

, as his dowry. Vygantas received Kuyavia

Kuyavia

Kujawy , is a historical and ethnographic region in the north-central Poland, situated in the basin of the middle Vistula and upper Noteć Rivers, with its capital in Włocławek.-Etymology:The origin of the name Kujawy was seen differently in history...

 from Jogaila instead. In 1388 he supported Poland in an armed conflict with the Teutonic Knights. He also supported Jogaila in the Lithuanian Civil War (1389–1392)

Lithuanian Civil War (1389–1392)

The Lithuanian Civil War of 1389–1392 was the second civil conflict between Jogaila, King of Poland and Grand Duke of Lithuania, and his cousin Vytautas the Great. At issue was control of the Grand Duchy of Lithuania, then the largest state in Europe. Jogaila had been crowned King of Poland in...

 against Vytautas the Great

Vytautas the Great

Vytautas ; styled "the Great" from the 15th century onwards; c. 1350 October 27, 1430) was one of the most famous rulers of medieval Lithuania. Vytautas was the ruler of the Grand Duchy of Lithuania which chiefly encompassed the Lithuanians and Ruthenians...

. Vygantas was considered as a replacement for unpopular Skirgaila

Skirgaila

Skirgaila , also known as Ivan; ca. 1353 or 1354 – 11 January 1397 in Kiev; baptized 1383/1384 as Casimir) was a regent of the Grand Duchy of Lithuania for his brother Jogaila from 1386 to 1392. He was son of Algirdas, Grand Duke of Lithuania, and his second wife Uliana of Tver.-Biography:After...

 as Grand Duke of Lithuania. However, he soon died. The rumors had it that he was poisoned – either by Vytautas or Skirgaila. He is buried in Vilnius Cathedral

Vilnius Cathedral

The Cathedral of Vilnius is the main Roman Catholic Cathedral of Lithuania.It is situated in Vilnius Old Town, just off of Cathedral Square. It is the heart of Lithuania's Catholic spiritual life....

 together with his brother Karigaila

Karigaila

Karigaila was a son of Algirdas, Grand Duke of Lithuania, and his second wife Uliana of Tver. He became the ruler of Mstsislaw after he captured it from the Principality of Smolensk. He is sometimes mistaken for his brother Constantine, who was the founder of the House of Czartoryski...

, who died in the civil war in 1390.

Vygantas should not be confused with his brother Andrei of Polotsk

Andrei of Polotsk

Andrei of Polotsk was the eldest son 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...

, who is sometimes referred to as Wigunt-Andrei following confused 15th-century chronicles of Jan Długosz. Kazimierz Stadnicki in his work Bracia Władysława-Jagiełły Olgierdowicza (published in 1867) suggested that Vygantas and his elder brother Theodore were the same person, but this theory was rejected.