The Treaty of Lyck was a treaty between 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...

, future Grand Duke of Lithuania, 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...

, represented by Marquard von Salzbach

Marquard von Salzbach

Marquard von Salzbach was a Teutonic Knight, who played a prominent role in shaping the relationship between the Knights and the Grand Duchy of Lithuania between 1389 and 1410....

, komtur

Komtur

Komtur was a rank within military orders, especially the Teutonic Knights. In the State of the Teutonic Order, the Komtur was the commander of a basic administrative division called Kommende . A Komtur was responsible for the alimentation of the Knights by the yield from the local estates, he...

Arnold von Bürglen, and Thomas, son of Lithuanian duke Survila. It was signed on January 19, 1390 in Lyck (now Ełk, Poland). Vytautas, in exchange for a military alliance against his cousin 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...

 during 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...

, agreed to cede Samogitia

Samogitia

Samogitia is one of the five ethnographic regions of Lithuania. It is located in northwestern Lithuania. Its largest city is Šiauliai/Šiaulē. The region has a long and distinct cultural history, reflected in the existence of the Samogitian dialect...

 up to the Nevėžis River

Nevežis River

Nevėžis River is the sixth longest river in Lithuania and one of the main tributaries of the Neman River. Its length is , and it flows only within the geographical confines of Lithuania. It is the second longest river in Lithuania, after the Šventoji River, that flows exclusively within its borders...

 and become the Order's vassal

Vassal

A vassal or feudatory is a person who has entered into a mutual obligation to a lord or monarch in the context of the feudal system in medieval Europe. The obligations often included military support and mutual protection, in exchange for certain privileges, usually including the grant of land held...

. In essence Vytautas confirmed the Treaty of Königsberg (1384)

Treaty of Königsberg (1384)

The Treaty of Königsberg was signed in Königsberg on January 30, 1384 during the Lithuanian Civil War between Vytautas the Great and representatives of the Teutonic Knights. Vytautas waged a civil against his cousin Jogaila, Grand Duke of Lithuania and future King of Poland, and allied himself...

 that he had signed with the Knights during the Lithuanian Civil War (1381–1384)

Lithuanian Civil War (1381–1384)

The Lithuanian Civil War of 1381–1384 was the first struggle for power between the cousins Jogaila, Grand Duke of Lithuania and later King of Poland, and Vytautas the Great. It began after Jogaila signed the Treaty of Dovydiškės with the Teutonic Knights which was aimed against his uncle Kęstutis,...

. Once betrayed, the Knights now asked for hostages as a guarantee of Vytautas' loyalty. The Order demanded as hostages his two brothers Sigismund

Sigismund Kestutaitis

Sigismund Kęstutaitis was the Grand Duke of Lithuania from 1432 to 1440. Sigismund was his baptismal name; Sigismund's pagan Lithuanian birth name is unknown. He was son of the Grand Duke of Lithuania Kęstutis and his wife Birutė....

 and Tautvilas, wife Anna, daughter Sophia

Sophia of Lithuania

Sophia was the only daughter of Vytautas the Great of Lithuania and his first wife Anna. On January 21, 1391, while her father was engaged in the Lithuanian Civil War, she married Vasili I of Russia. She was the longest serving consort of Russia.After his death in 1425 she became regent for their...

, sister Rymgajla

Rymgajla

Rymgajla was daughter of Birutė and Kęstutis, Grand Duke of Lithuania, and thus sister of Vytautas the Great. Rimgailė is a typical dual-stemmed pagan Lithuanian name constructed from rim- + gail- , which is quite common in Lithuania at present.By marriage with Henry of Masovia, she was Princess of...

, brother-in-law Ivan Olshanski

Ivan Olshanski

Ivan Olshanski is the first known and undisputed member of the princely Olshanski family. Historians only know his fathers name, Algimantas. Ivan was a faithful companion of Vytautas the Great, Grand Duke of Lithuania. They both were married to daughters of Sudimantas of Eišiškės...

, and a number of other nobles.

Vytautas initiated the negotiations when he failed to capture Vilnius

Vilnius

Vilnius is the capital of Lithuania, and its largest city, with a population of 560,190 as of 2010. It is the seat of the Vilnius city municipality and of the Vilnius district municipality. It is also the capital of Vilnius County...

, capital of the Grand Duchy of Lithuania

Grand Duchy of Lithuania

The Grand Duchy of Lithuania was a European state from the 12th /13th century until 1569 and then as a constituent part of Polish-Lithuanian Commonwealth until 1791 when Constitution of May 3, 1791 abolished it in favor of unitary state. It was founded by the Lithuanians, one of the polytheistic...

. He sent Marquard von Salzbach and the Count of Rheineck

Rheineck

Rheineck is a municipality in the Wahlkreis of Rheintal in the canton of St. Gallen in Switzerland.-History:Rheineck is first mentioned about 1163 as castellum Rinegge. In 1218 it was mentioned as Rinegg...

, two knights held captive since 1384, to negotiate on his behalf. The treaty was signed in secret as not to alert 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...

 and his brother 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...

. The Knights managed to convince Skirgaila that they were ready to negotiate peace with him, and he even returned from Polotsk to Vilnius

Vilnius

Vilnius is the capital of Lithuania, and its largest city, with a population of 560,190 as of 2010. It is the seat of the Vilnius city municipality and of the Vilnius district municipality. It is also the capital of Vilnius County...

 anticipating the Teutonic envoy.

The Treaty of Lyck was strengthened by the Treaty of Königsberg (1390)

Treaty of Königsberg (1390)

The Treaty of Königsberg was signed in Königsberg on May 26, 1390 during the Lithuanian Civil War between Samogitian nobles and representatives of the Teutonic Knights. The 31-member or 30-member delegation from seven Samogitian regions arrived to Königsberg around pentecost...

, signed between the Knights and a Samogitian delegation, which promised its loyalty to the "Samogitian king" Vytautas. The Knights helped Vytautas to wage a war against Jogaila, but the cousins reconciled in 1392 and signed the Ostrów Agreement

Ostrów Agreement

The Ostrów or Astrava Agreement was a treaty between Jogaila , King of Poland and Grand Duke of Lithuania, and his cousin Vytautas the Great, signed on August 4, 1392...

. The Knights were once again betrayed: Vytautas burned three of their castles and did not cede Samogitia. They continued to wage war until the Treaty of Salynas

Treaty of Salynas

Treaty of Salynas was a peace treaty signed on October 12, 1398 by the Grand Duke of Lithuania Vytautas the Great and the Grand Master of the Teutonic Knights Konrad von Jungingen. It was signed on an islet of the Neman River, probably between Kulautuva and the mouth of the Nevėžis River...

 of 1398; territorial disputes over Samogitia dragged until the Treaty of Melno

Treaty of Melno

The Treaty of Melno or Treaty of Lake Melno was a peace treaty ending the Gollub War. It was signed on September 27, 1422, between the Teutonic Knights and an alliance of the Kingdom of Poland and the Grand Duchy of Lithuania at Lake Melno , east of Graudenz...

of 1422.