Sigismund Kęstutaitis (, ; 136520 March 1440) was

Grand Duke of Lithuania This is a list of Lithuanian monarchs who ruled Lithuania from its inception until the fall of the Grand Duchy of Lithuania in 1795. The Lithuanian monarch bore the title of Grand duke, Grand Duke, with the exception of Mindaugas, who was crown ...

from 1432 to 1440.

Sigismund Sigismund (variants: Sigmund, Siegmund) is a German proper name, meaning "protection through victory", from Old High German ''sigu'' "victory" + ''munt'' "hand, protection". Tacitus latinises it ''Segimundus''. There appears to be an older form of ...

was his

baptismal name A Christian name, sometimes referred to as a baptismal name, is a religious name, religious personal personal name, name given on the occasion of a Christian baptism, though now most often given by parents at birth. In Anglosphere, English-spe ...

, while his pagan Lithuanian birth name is unknown. He was the son of Grand Duke

Kęstutis Kęstutis ( – 3 or 15 August 1382) was sole Duke of Trakai from 1342 to 1382 and List of Lithuanian monarchs, Grand Duke of Lithuania from 1342 to 1382, together with his brother Algirdas (until 1377), and with his nephew Jogaila (from 1377 to ...

and his wife Birutė. After the death of

, he was a prisoner of Jogaila from 1382 to 1384. Sigismund was baptized in the Catholic rite in 1383. In 1384, he escaped captivity and joined his brother

Vytautas Vytautas the Great (; 27 October 1430) was a ruler of the Grand Duchy of Lithuania. He was also the prince of Grodno (1370–1382), prince of Lutsk (1387–1389), and the postulated king of the Hussites. In modern Lithuania, Vytautas is revere ...

, who allied himself with the

Teutonic Knights The Teutonic Order is a Catholic religious institution founded as a military society in Acre, Kingdom of Jerusalem. The Order of Brothers of the German House of Saint Mary in Jerusalem was formed to aid Christians on their pilgrimages to t ...

. When Vytautas allied with the Teutonic Knights for the second time to fight Skirgaila, Sigismund was a hostage of the Teutonic Knights, together with his family from 1389 to 1398. He became Duke of Navahrudak (1390–1440), and

Starodub Starodub (, , ) is a types of inhabited localities in Russia, town in Bryansk Oblast, Russia, on the Babinets (river), Babinets River in the Dnieper basin, southwest of Bryansk. Population: 16,000 (1975). History Starodub has been known ...

from 1406. He participated in the Battles of Vorskla and the Grunwald. After the death of Vytautas, he supported his cousin

Švitrigaila Švitrigaila (before 1370 – 10 February 1452; sometimes spelled Svidrigiello) was the Grand Duke of Lithuania from 1430 to 1432. He spent most of his life in largely unsuccessful dynastic struggles against his cousins Vytautas and Sigismund K� ...

in his fight against

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...

, but later was convinced by nobles to join a conspiracy against him. On 1 September 1432, Sigismund became the Grand Duke of Lithuania. He signed the Union of Grodno with Jogaila and ceded some territories in

Volhynia Volhynia or Volynia ( ; see #Names and etymology, below) is a historic region in Central and Eastern Europe, between southeastern Poland, southwestern Belarus, and northwestern Ukraine. The borders of the region are not clearly defined, but in ...

and

Podolia Podolia or Podillia is a historic region in Eastern Europe located in the west-central and southwestern parts of Ukraine and northeastern Moldova (i.e. northern Transnistria). Podolia is bordered by the Dniester River and Boh River. It features ...

to Poland. However, Švitrigaila was still active and had the support of many Eastern Orthodox nobles. In 1434, in an attempt to attract support from these nobles, he issued a privilege to nobles of

Eastern Orthodox Eastern Orthodoxy, otherwise known as Eastern Orthodox Christianity or Byzantine Christianity, is one of the three main Branches of Christianity, branches of Chalcedonian Christianity, alongside Catholic Church, Catholicism and Protestantism ...

faith, making their rights equal to those of noble

Roman Catholics The Catholic Church (), also known as the Roman Catholic Church, is the largest Christian church, with 1.27 to 1.41 billion baptized Catholics worldwide as of 2025. It is among the world's oldest and largest international institut ...

. He guaranteed that no noble, regardless of religion, could be imprisoned or punished without a court order. The privilege was an important development and accelerated the formation of a

feudal system Feudalism, also known as the feudal system, was a combination of legal, economic, military, cultural, and political customs that flourished in medieval Europe from the 9th to 15th centuries. Broadly defined, it was a way of structuring socie ...

. Sigismund's army defeated Švitrigaila in the

Battle of Wiłkomierz The Battle of Wiłkomierz (see Battle of Wilkomierz#Names, other names) took place on September 1, 1435, near Ukmergė in the Grand Duchy of Lithuania. With the help of military units from the Kingdom of Poland (1385–1569), Kingdom of Poland, t ...

on 1 September 1435. The

Livonian Order The Livonian Order was an autonomous branch of the Teutonic Order, formed in 1237. From 1435 to 1561 it was a member of the Livonian Confederation. History The order was formed from the remnants of the Livonian Brothers of the Sword after thei ...

, an ally of Švitrigaila, suffered a major defeat. After strengthening his positions in Lithuania, he tried to loosen his ties with Poland and negotiated between 1438 and 1440 with Albert of Hungary (who was also the German king) for an anti-Polish alliance, but was killed by supporters of Švitrigaila (possibly led by Alexander Czartoryski) at the

Trakai Peninsula Castle Trakai Peninsula Castle is one of the castles in Trakai, Lithuania. It is located on a peninsula between southern Lake Galvė and Lake Luka. Built around 1350–1377 by Kęstutis, Duke of Trakai, it was an important defensive structure protecting ...

on 20 March 1440. Sigismund had one son, named Michael Žygimantaitis, who died shortly before 10 February 1452.

References

* * {{Authority control 1360s births 1440 deaths 15th-century dukes in Europe 15th-century murdered monarchs Burials at Vilnius Cathedral Date of birth unknown Gediminids Grand dukes of Lithuania People in the Battle of Grunwald

See also

References