Jogaila (Polish: Jogaila), also known as Jogaila and later W ł adys ł aw II Jagie ł o (Polish: W ł adys ł aw II Jagie ł o, approximately 1362-1434), was the Grand Duke of Lithuania and King of Poland, and the founder of the Jagiellonian dynasty.
Jagiello ruled the Grand Duchy of Lithuania from 1377, and at the beginning of his term, he co ruled with his uncle Kostutis. In 1386, Jagiellonian adopted the Catholic name W ł adys ł aw and married Queen Jadwiga of Poland. He was crowned King of Poland in the name of W ł adys ł aw Jagiellonian. Thus, the Jagiellonian dynasty was established for nearly two hundred years. He was the last pagan ruler of medieval Lithuania, with the title Didysis Kunigaik š tis. As the King of Poland, Jagiello pursued a policy of forming an alliance with Lithuania to resist the Teutonic Knights. In 1410, Jagiello led the Polish Lithuanian coalition to a great victory over the Teutonic Knights in the Battle of Grunwald, and the subsequent ceasefire of Sonne stabilized the border between Poland and Lithuania. In his later years, he was embroiled in a long war with the Teutonic Knights and political struggles in Lithuania. In 1434, Yagewo passed away.
Jagiello ruled Poland for 48 years and is regarded as the founder of the later Polish Lithuanian Commonwealth. During his reign, Poland's territory expanded, and his reign is often considered Poland's "golden age".

Early life
Yagewo's early experiences are little known, and even his birthday is controversial. Previous historians believed that he was born in 1352, but recent research suggests that his birth date was slightly later than previous studies - around 1362. He is a descendant of the Gediminez dynasty and may have been born in Vilnius. His parents were Grand Duke Akildas of the Grand Duchy of Lithuania and his second wife, Uliana Alexandrovna, daughter of King Alexander I of Tver. [6]
After the death of Akhirdas in 1377, Jagiello successfully merged Lithuania, which was composed of two different ethnic groups and two political systems: Lithuania in the northwest and Ruthenia located in present-day Ukraine, Belarus, and western Russia, inheriting the vast territory of former Kievan Rus, into a stable political entity. At first, Jagiello, like his father who besieged Moscow in 1370, based on his territory in southeastern Lithuania, while his uncle, Duke Kostutis of Chukchi, continued to rule the northeastern region. Regardless of the circumstances, Yagewo, who ascended to the throne, quickly tightened this dual ruling system.
At the beginning of his term, the turmoil in Lithuania led Jagiello to focus on the Ruthenian region of Lithuania. From 1377 to 1378, for example, his half brother Andrei of Polotsk, who had been Russified, prepared to leave Moscow. In 1380, Andrei and the Grand Duke of Moscow Dimitri fought against the ally of Yagevo, the Golden Horde's Mamai. Yagevo failed to support Mamai's army in a timely manner with his army, and as a result, Mamai was defeated by the Grand Duke of Moscow Dimitri in the Battle of Kurikovo. Afterwards, the Moscow Principality created a greater threat to Lithuania. In the same year, Yagevo opposed Kostutis for the highest power.

In the northwest, Lithuania faced attacks from armed Teutonic Knights. In 1380, Jagiellonian secretly signed the Treaty of Dolittislas with the Knights, in which he agreed to Christianize Lithuania and in return, the Knights would support him in his opposition to Kostutis. When Kostutis discovered this plan, the Lithuanian Civil War was launched. He occupied Vilnius, overthrew Yagevo, and proclaimed himself Grand Duke in his place.
In 1382, Yagevo established an army among his father's vassals and faced Kostutis head-on near Chaki. Kostutis and his son Vytautas negotiated with Yagevo's brother at Yagevo's camp in Vilnius based on Skirgala's promise of safe passage, but were deceived and banned from the castle of Kleva, where Kostutis died, possibly murdered a week later. Vytautas fled to the Teutonic Castle of Marburg and was baptized, taking the religious name Vigande. [1]
During further talks between Jagiello and the Knights, the Treaty of Dubisar was signed, which reaffirmed his commitment to Christianization and promised to grant the Knights the Samogitian region west of the Dubisar River. Anyway, the Knights claimed to immediately help their two brothers and entered Lithuania in the summer of 1383, occupying most of Samogitia and opening the way for the Prussian Teutonic Knights and the Livonian Teutonic Knights further north. Along with the Knights, Vytautas, who carried weapons, accepted Jagiellonian's guarantee regarding his inheritance and attacked with him, plundering some Prussian castles.

Baptism and Marriage
When the time came for Jagiello to choose his wife, it had become clear that he intended to marry a Christian. His Russian mother hoped that he would marry Sofia, the daughter of Dmitry Donskoy, who first demanded that he convert to Eastern Orthodoxy. However, this choice did not stop the Crusaders led by the Teutonic Knights, who believed that Orthodox Christians were supporters of church division and were no different from pagans attacking Lithuania.
Jagiello therefore accepted a Polish proposal, converted to Catholicism, and married the 11 year old Queen Jadwiga. He was also legally accepted by Jadwiga's mother, Elizabeth of Hungary, so he was able to retain the throne even when Jadwiga died. Regarding these and other issues, on August 14, 1385, at the Castle of Kareva, Jagiello agreed to accept Christianity and return the land "stolen" from Poland by its neighbors to Poland, and the two sides reached the so-called "Klevo Union". This clause is interpreted by historians as meaning that any individual treaty signed between Lithuania and Poland prior to marriage will be replaced by a joint treaty at the time of marriage. Klevo Union is described as a cautious or desperate gamble.

Jagiello was baptized on time at the Wawel Cathedral in Krakow on December 15, 1386, and subsequently used W ł adys ł aw or its Latin version. The official announcement of baptism was handed over to Grand Master Ernst von Zoller, who refused to become the new Christian Godfather, at the headquarters of the Knights in Marburg. The royal baptism triggered the conversion of the Jagiellonian court and knights, and also gathered the baptized in the rivers of Lithuania, marking the beginning of Lithuania's ultimate Christianization. The annexation of Jagiellonian and its political significance have had a profound impact on the history of Lithuania and Poland. [2]
Before W ł adys ł aw arrived in Krakow, Queen Jadwiga sent her knight Gavisha Orensteicki to investigate her future husband. Because she heard he was a bear like creature, cruel and rude. Despite Jadwiga's doubts, the wedding was still held on March 4, 1386, two weeks after Jagiello's baptism, and Jagiello was crowned King W ł adys ł aw Jagiello of Poland by Archbishop Poynta. Finally, the Poles discovered that their new ruler was a very cultured monarch who highly respected Christian culture, as well as a seasoned politician and commander. He is a robust person with small and restless black eyes and big ears. W ł adys ł aw dresses very carefully and is said to be exceptionally clean. He cleans himself every day, shaves, never smokes, and only drinks pure water. His entertainment methods include listening to Ruthenian violin music and hunting. Some medieval chroniclers believe that W ł adys ł aw's astonishing changes were due to his loyalty.
Co rule Poland
Co governance of W ł adys ł aw and Jadwiga; Although Jadwiga may not have real power, she still actively participates in Poland's political and cultural development. In 1387, she led two successful expeditions against Red Ruthenia, reclaiming the land her father had given to Hungary from Poland and earning the respect of Petrus I. In 1390, she also personally opened the door to negotiations with the Teutonic Knights. Although most of the political responsibility was entrusted to W ł adys ł aw, Jadwiga remained committed to cultural and charitable activities, earning her continued respect.
Soon after, W ł adys ł aw ascended to the throne in Poland and granted Vilnius and Krakow a city constitution designed in accordance with the Magdeburg Law; Moreover, during the reigns of Boleslaw and Casimir III, Vytautas granted privileges to the Jewish community of Chaki. The implementation of the policy of unifying the two legal systems in W ł adys ł aw was initially incomplete and bumpy, but it had a lasting impact.

One of the impacts of W ł adys ł aw's policy was the increasing number of Lithuanian Catholics while undermining the foundation of Eastern Orthodoxy; In 1387 and 1413, for example, the Lithuanian Catholic Bovary was granted special judicial and political powers, while the Eastern Orthodox Bovary was stripped of its power. As this momentum continued to strengthen, Lithuania rose in the 15th century along with the rise of the former Rus. [3]
Facing challenges
The baptism of W ł adys ł aw did not completely stop the Teutonic Knights' Crusade invasion, which claimed that his baptism was just a facade and may even be pagan, and reiterated their claim that Lithuania still had an excuse for pagan invasion. From now on, however, the Knights have found it difficult to sustain the excuse of launching the Crusades and face the elimination of the true Christian country Lithuania's reasons for launching the Crusades.
In short, W ł adys ł aw and Jadwiga's policies towards Christianized Lithuania provided a reason for the Teutonic Knights to oppose Lithuania, rather than a reason for the Knights to disarm. They initiated the establishment of the Vilnius Diocese under the rule of the former Confessor Bishop of Vilnius, Andrei Vahirk. The bishopric includes Samogitia, which is largely controlled by the Teutonic Knights and subordinate to Gniezno, rather than the Teutonic Knights' K ö nigsberg. This decision may not have improved the relationship between the Teutonic Knights and W ł adys ł aw, but it made the relationship between Lithuania and Poland closer, allowing the Polish Church to freely assist its peers in Lithuania.
In 1389, W ł adys ł aw's rule in Lithuania was threatened as Vytautas returned to Lithuania and launched a civil war in an attempt to seize the position of Grand Duke. On September 4, 1390, the coalition led by Vytautas and Teutonic Knights Commander Conrad von Valenrod besieged Vilnius, but after a month of attack, they were still unable to capture the city and were forced to lift the siege on the castle. This bloody battle finally achieved a temporary ceasefire in 1392 according to the Treaty of Ostrov, which entrusted Lithuania to his distant relatives in order to obtain a brief peace: Vytautas ruled Lithuania as Grand Duke until his death, obeying the supreme power of the king or duke personally assumed by the Polish monarch. Vytautas accepted his identity, but he continued to demand complete independence for Lithuania.

The protracted war between the Lithuanians and the Teutonic Knights finally ended on October 12, 1398, according to the Treaty of Salinas. Lithuania agreed to cede Samogitia and assist the Teutonic Knights in the Battle of Pskov, while the Knights also agreed to assist Lithuania in the Battle of Novoglod. Shortly thereafter, Vytautas became a local noble crowned by the king; But in the following year, his army and his allies, the White Horde, were lost in the Battle of Volskola and defeated by the Central Asian tyrant Timur, forcing Vytautas to once again submit to W ł adys ł aw.
Consolidate the throne
On June 22, 1399, Jadwiga gave birth to a daughter named Erzbeta Bonifacia. But within a month, Jadwiga and her daughter both died from complications during childbirth, leaving Yagevo, who was 50 years old and childless. The death of Jadwiga and the extinction of the Anjou dynasty gradually weakened the royal power of W ł adys ł aw; And due to conflicts between the nobility of Lesser Poland, factions sympathetic to W ł adys ł aw and gentlemen of Greater Poland began to emerge. In 1402, as a response to his opponents, W ł adys ł aw married Anna of Chelle, the granddaughter of Casimir III, and re established his legitimate rule.
In 1401, Vilnius and Radom jointly confirmed that Vytautas was the second Grand Duke to the power of W ł adys ł aw, while ensuring that the heir of the Grand Duke was a descendant of W ł adys ł aw, not a descendant of Vytautas: if W ł adys ł aw died childless, Lithuanian Powi would elect a new monarch. Due to the lack of an heir to the throne, the impact of this bill is unknown, but it has brought the relationship between Polish and Lithuanian nobility closer, and the two countries have formed a permanent defensive alliance, strengthening Lithuania's hand and enabling it to launch a war against the Teutonic Knights that Poland did not participate in. Although this document does not affect the freedom of Polish nobles, it acknowledges the expansion of power in Lithuanian Powel, and the Grand Duke is still not subject to the checks and balances that may arise from being dependent on Poland. Therefore, Vilnius and Radom joined forces to gain support from Lithuania for W ł adys ł aw.

At the end of 1401, a new war launched against the Order of Knights resulted in a rebellion in the eastern provinces, and it was discovered that the resources of the Lithuanians who were fighting on both fronts were becoming scarce. Another brother of W ł adys ł aw, the dissatisfied Svetla, took advantage of this opportunity to launch an uprising and proclaimed himself Grand Duke. On January 31, 1402, he received the support of the Knights.
The war is over and W ł adys ł aw has been defeated. In the Treaty of Lachaz on May 22, 1404, he accepted most of the demands of the Knights, including the formal cession of Samogitia and support for the Knights' siege of Pskov; In return, Conrad von Junlingen promised to sell the controversial Dobkin area and the town of Zotolia, which had been mortgaged to the Knights by W ł adys ł aw Oppelski, to Poland, and supported Vytautas' re-entry into politics in Novoglod. The main reason for both sides signing this treaty is that the Knights need time to defend their newly acquired land, and the Poles and Lithuanians need to deal with sovereignty threats in the east and Silesia.
In 1404, at W ł adys ł aw in Wroc ł aw, talks were held with King Wenceslaus IV of Bohemia, who supported him in the political struggles of the Holy Roman Empire and was willing to return Silesia to Poland. W ł adys ł aw refused to trade on the agreement between the Polish and Silesian nobles because he was unwilling to increase his burden due to new military commitments.

The Teutonic Wars
The Vahrudak Castle talks
In December 1408, W ł adys ł aw and Vytautas held strategic talks at the Nawahrudak Castle and decided to incite a rebellion among the Samogitians who were resisting the rule of the Teutonic Knights, in order to drive the Germans out of Pomerania. W ł adys ł aw promised to return Samogitia to Lithuania in any future treaty as a reward for his support from Vytautas. The uprising that began in May 1409 did not initially attract much attention from the Knights, but in June, their diplomats began busy lobbying the courts of W ł adys ł aw in Oboniki, warning him against the nobles involved in the war between Lithuania and the Knights. Although W ł adys ł aw avoided his nobles and told the newly appointed Grand Marshal Ulrich von Junlingen that if the Knights suppressed Samogitia, Poland would intervene in them. The Knights ultimately decided to declare war on Poland on August 6th, and this news was received by W ł adys ł aw on August 14th in Novi Korchin.
Due to negligence on the northern border, the Knights easily occupied the capital of Zotolia, Doblin, and the Doblin region, Bobryniki, while German citizens also invited them to enter Bydgoszcz. During this period, W ł adys ł aw only organized an army to recapture Bydgoszcz within a week in September, but on October 8th, the city was recaptured by the Knights. In fact, W ł adys ł aw was currently setting up a strategic supply depot in Prwotsk, Mazovia, and constructing a floating bridge on the Vistula River to transport supplies northward in preparation for the upcoming decisive battle.
At the same time, both sides launched a diplomatic offensive. The Knights sent a letter to the monarchs of Europe, asking them to send Crusaders to suppress the 'infidels'; W ł adys ł aw responded to the Knights' diplomatic offensive by sending his handwritten letter to the monarchs of the Order of Duty who wanted to conquer the world. This offensive successfully recruited many foreign knights into all sides of the battle. Wenceslaus IV and the Poles signed a defense treaty to jointly resist the Teutonic Knights; His brother, Sigismund, joined the side of the Knights and declared war on Poland on July 12th.

Bitwa pod Grunwaldem
When the war resumed in June 1410, W ł adys ł aw led 20000 nobles, 15000 armed civilians, and 2000 professional cavalry primarily employed in Bohemia deep into the heartland of the Teutonic Knights. After crossing the Vistula River in Chervensko, his army joined forces with Vytautas, who led 11000 Ruthenian and Tatar light cavalry. The Teutonic Knights had 18000 cavalry and 5000 infantry, almost all of whom were Germanic. On June 15th, the Battle of Grunwald, the largest and most brutal battle of the Middle Ages, resulted in a complete victory for the Alliance, causing the entire army of the Teutonic Knights to be wiped out. During the battle, most of the key commanders of the Knights were killed, including Grand Marshal Ulrich von Junlingen and Grand Marshal Friedrich von Valenrod. The army of over a thousand people reported being wiped out by the other side.
Now, the road leading to Teutonic headquarters in Marburg is open and the city is undefended; But because the information was not explained clearly, W ł adys ł aw hesitated about his favorable conditions. On July 17th, his army began a difficult advance and only arrived in Marburg on July 25th. At the same time, the new commander Heinrich von Plaun began to deploy the defense of the fortress. Obviously, the half hearted siege led W ł adys ł aw to halt the siege on September 19th. The failure of this siege was attributed to the high casualty rate of Lithuanians caused by various defense works that could not be breached, and W ł adys ł aw was unwilling to cause further casualties; However, the lack of information makes this possibility unstable. Pavel Yashnica pointed out in his monument Polska Jagiellon ó w (Jagiellon's Poland) that as a Lithuanian, W ł adys ł aw may have hoped to maintain the balance of power between Lithuania and Poland, as Lithuanians endured extremely heavy casualties in the battle. Other historians point out that W ł adys ł aw may have believed that Marburg was impregnable, so he did not see his advantage, but they did not necessarily succeed in the long siege.