The Polish–Teutonic War of 1431–1435 or Lithuanian Civil War of 1431–1435 was a war over the succession to the throne of the Grand Duchy of Lithuania fought between Švitrigaila and Poland-backed Sigismund Kęstutaitis after Vytautas the Great died in 1430 without leaving an heir. Švitrigaila allied himself with the Grand Master of the Teutonic Order, Paul von Rusdorf, against the Kingdom of Poland. Rusdorf's intervention in the Lithuanian succession dispute proved to be a failure. When Sigismund captured power in Lithuanian by staging a coup in 1432, Lithuania split into two opposing camps and three years of devastating hostilities began. To prevent the Knights from continuing their support to Švitrigaila, Poland supported Hussite invasion in Prussia in 1433. The war ended in a decisive defeat suffered by Švitrigaila and his ally, the Livonian branch of the Knights, in the Battle of Pabaiskas in September 1435. Švitrigaila eventually surrendered in 1437; Sigismund Kęstutaitis ruled Lithuania for only eight years as he was assassinated in 1440.

Prelude

On October 27 1430 Vytautas the Great, Grand Duke of Lithuania, died suddenly without leaving an heir or a will. His coronation as King of Lithuania was scheduled for September 1430; however, Poles stopped the crown from reaching Lithuania. Vytautas' only daughter Sophia of Lithuania was married to Vasily I of Moscow and had only one surviving son, Vasily II. He was Orthodox and could not lead the recently christianized Catholic Grand Duchy. Orthodox faith prevented many other Gediminids from becoming pretenders to the throne. There were two most suitable Catholic candidates: Vytautas' brother and technically the legal heir, Sigismund Kęstutaitis, and Vytautas' cousin Švitrigaila.

Lithuanian nobles unilaterally elected Švitrigaila as the Grand Duke. This violated the terms of the Union of Horodło of 1413, where Lithuanians promised not to elect a new Grand Duke without the approval of the Kingdom of Poland. In order to receive Ruthenian votes Švitrigaila granted equal rights to Catholic and Orthodox nobles – it was one lasting achievement of his brief reign. Švitrigaila asked Sigismund, Holy Roman Emperor to send him the crown intended for Vytautas. The Polish noblity, led by Zbigniew Oleśnicki, were outraged and demanded that Švitrigaila acknowledged his fealty to his brother Jogaila, King of Poland. Švitrigaila refused and professed full independence. The conflict was further complicated by territorial disputes in Podolia and Volhynia, that according to an agreement in 1411 were to be ruled by Lithuania only for the lifetime of Vytautas.

Teutonic invasion to Poland

Švitrigaila fought with the Polish–Lithuanian forces at Lutsk in Volhynia, and at the same time started organizing a wider anti-Polish coalition. He negotiated with the Teutonic Knights, Sigismund, Holy Roman Emperor, Moldavia, the Golden Horde, dukes of eastern lands of the Grand Duchy of Lithuania. The most promising ally was the Teutonic Order, which sought to undo the Polish–Lithuanian union which led to its defeat in the Battle of Grunwald in 1410. In June 1431 the Treaty of Christmemel (modern Skirsnemunė) was signed between the Teutonic Knights and Švitrigaila. Švitrigaila's cause was also aided by Moldavian forces, lead by Alexander the Good, who attacked Poland in southeast.

According to the agreement of Christmemel the Teutonic Knights declared war and invaded Poland, whose forces where engaging Švitrigaila in Volhynia. Finding little opposition, they ravaged Dobrzyń Land, taking the town of Nieszawa and tried to move to Kuyavia and Krajna regions. However, the Teutonic army was defeated on September 13 1431 at Dąbki, near Nakel (modern Nakło nad Notecią). In September a two-year truce between Poland, Lithuania, and the Teutonic Knights was signed in Staryi Chortoryisk. It was more favorable to Poland and it is not clear why Švitrigaila agreed to it. However, the truce did not solve the underlying dispute. The war turned into diplomatic struggle: Poland sought to turn Lithuanian nobles against Švitrigaila.

Coup in Lithuania

Conspirators, led by Sigismund Kęstutaitis, attacked Švitrigaila and his escort, who were staying in Ašmena for the night of August 31 1432. Švitrigaila managed to escape to Polotsk. It is unclear what groups supported Sigismund and why. Possibly Lithuanian nobles were dissatisfied with favors Švitrigaila showed to Orthodox dukes, but before the coup no such opposition showcased itself. Sigismund, who did not play a major role in Lithuanian politics before the coup and who initially supported Švitrigaila, became the Grand Duke and resumed policy of union with Poland. On October 15 1432 he signed the Union of Grodno, which in essence confirmed the Union of Vilnius and Radom (1401) and granted Sigismund the same rights as Vytautas enjoyed during his reign. After Sigismund's death, Lithuania was to return to King of Poland. Sigismund also made territorial concessions to Poland in disputed Podolia and Volhynia.

To win support from the nobles, Sigismund granted privileges in May 1434 to to both Catholic and Orthodox nobles. The privilege guaranteed their rights to buy, sell, exchange, gift, and inherit land. Veldamas, a class of dependent peasants, was released from its taxes and duties to the state – all their earnings now belonged to the nobles. No noble was to be punished or imprisoned for crimes without a court order. Lithuania was divided into two camps: supporters of Sigismund (Lithuanian lands, Samogitia, Podlachia, Hrodna, Minsk) and supporters of Švitrigaila (Polotsk, Vitebsk, Smolensk, Kiev, Volhynia). Three years of devastating hostilities began. On December 8 1432 armies of Švitrigaila and Sigismunt met near Ašmena. Švitrigaila enlisted help from Sayid Ahmad I, Khan of the Golden Horde, and planned to attack capital of the Grand Duchy, Vilnius, and return to the throne. Both sides suffered heavy losses and final victory went to Sigismund. The Order officially observed the truce but continued secret support of Švitrigaila mostly through its Livonian branch.

Hussite invasion to Prussia

In June 1433 Poland allied itself with the Czech Hussites in order to stop the Order sending secret support to Švitrigaila via its Livonian branch. The Teutonic Knights supported the pope and Sigismund, Holy Roman Emperor against heretic Hussites during the Hussite Wars. Czech forces under Jan Čapek of Sány were granted safe passage through Poland for their biggest and last "beautiful ride." The Polish forces were also supported by Pomeranian duke Bogusław IX (from the Duchy of Stolp (Słupsk)). In addition, the Moldavians, whose ruler Iliaş was replaced by more pro-Polish Stephen II, have joined the Polish alliance. The Hussite army, including forces led by Feodor Ostrogski, ravaged Teutonic territories in Neumark, Pomerania, and western Prussia for four months. First they unsuccessfully besieged Konitz (modern Chojnice) and then moved north to Schwetz (modern Świecie) and Danzig (modern Gdańsk). They captured several towns and castles, including Dirschau (modern Tczew) on the Vistula River on August 29 1433. Despite the failed siege of Danzig, Hussites celebrated their "beautiful ride" by symbolically filing their bottles with water from the Baltic Sea.

A truce was signed on September 13 1433 in Jasiniec. Polish–Teutonic negotiations were continued in Brześć Kujawski and Hussite–Catholic negotiations continued in the Council of Florence and Czech Diet in Prague. The Polish led invasion of Neumark and Pomerania proved to be successful, cutting of the Order from any support from the Holy Roman Empire, and convincing them to sign a treaty with Poles. While the leaders of the Order were willing to fight, the citizens of Prussia demanded an immediate end to the war. Finally a twelve-year truce was signed between Poles and the Order in Łęczyca on December 15 1433 (this has also led some Polish historians to divide this Polish–Teutonic War into two wars, in 1431–1433 and in 1435). The Teutonic Knights agreed in addition to the 12-year old truce to other Polish demands, including that the Order would cease support to Švitrigaila; in addition each side would control the territories it occupied until a peace would be signed (uti possidetis), and no party would seek mediation of foreign powers to change this truce. This marked the end of the war on Polish territories; the struggle on Lithuanian lands would continue for two more years (as the truce with Poland did not extend to the Livonian Order).

Jogaila's alliance with heretics damaged his reputation and earned him excommunication from the pope. By 1433 however Jogaila had gained favor with the Church, particularly due to the fact that Švitrigaila had allied himself with the Islamic Tatars. Jogaila received tithes from the Church (which expected him to combat both the Tatars and the Hussites), and his representatives were invited to be heard in front of the ecumenical council at Florence.

Decisive battle and aftermath

In July and August 1433, Švitrigaila and his Livonian allies raided Lida, Kreva, Eišiškės and devastated suburbs of Vilnius, Trakai, and Kaunas. The hostilities were briefly stopped by horse plague. When Jogaila died in May 1434, the Order resumed its support to Švitrigaila, who rallied his supporters, including knights from the Livonian Order, Orthodox dukes, and his nephew Sigismund Korybut, distinguished military commander of the Hussites. The final Battle of Pabaiskas was fought in September 1435 near Ukmergė (Vilkomir, Wiłkomierz). It estimated that the battle involved 30,000 men fighting on both sides. Švitrigaila's army, lead by Sigismund Korybut, was split in half by the attacking Lithuanian–Polish army, lead by Michael Žygimantaitis, and was soundly defeated.

Švitrigaila with a small group of followers managed to escape to Polotsk. The Livonian Order suffered a great defeat, sometimes compared to defeat inflicted upon the Teutonic Knights in the Battle of Grunwald of 1410. The Teutonic Knights signed peace treaty in Brześć Kujawski on December 31 1435. They agreed to cease their support to Švitrigaila and in the future to support only Grand Dukes properly elected jointly by Poland and Lithuania. The treaty did not change borders determined by the Treaty of Melno in 1422. The Peace of Brześć Kujawski showed that Teutonic Knights lost their universal missionary status. Teutonic and Livonian Order no longer interfered with Polish–Lithuanian affairs; instead Poland and Lithuania involved themselves in the Thirteen Years' War, the civil war in Prussia that tore it in half.

Švitrigaila was losing his influence in the Slavic principalities and could no longer resist Poland and Sigismund. On September 4 1437 he attempted to reconciled with Poland: he would rule lands that still supported him (chiefly Kiev and Volhynia) and after his death the territories would pass to the King of Poland. However, Polish Senate did not ratify this treaty under strong protest from Sigismund. Švitrigaila retreated to Moldavia in 1348. The reign of Sigismund Kęstutaitis was short – he was assassinated in 1440. Švitrigaila returned from his exile in 1442 and ruled Lutsk until his death a decade later.

References

Further reading

• Grodecki, Roman; Stanisław Zachorowski, Jan Dąbrowski (1995). Dzieje Polski Średniowiecznej. Kraków: Wydawnictwo Platan.
• Biskup, Marian; Gerard Labuda (1986). Dzieje zakonu krzyżackiego w Prusach. Gdańsk: Wydawnictwo Morskie.