Editing Władysław II Jagiełło (section)

===Lithuania===
Little is known of Jogaila's early life, and even his year of birth is uncertain. Previously historians assumed he was born in 1352, but some recent research suggests a later date—about 1362.<ref name="tęgowski">{{Harvnb|Tęgowski|1999|pp=124–125}}</ref> He was a descendant of the [[Gediminids|Gediminid dynasty]] and was the son of [[Algirdas]], Grand Duke of Lithuania, and his second wife, [[Uliana of Tver]],<ref>{{Harvnb|Potašenko|2008|p=30}}</ref> who was the daughter of the [[Yaroslav of Tver|Yaroslavichi]] prince [[Aleksandr of Tver]]. His name had a meaning of more courageous and superior than others, he spent most of his early time in [[Vilnius]], at his father's manor.<ref name="Plikune"/>

[[File:Coin of Jogaila with a lion (1386–1387).jpg|thumb|left|Early coin of the [[Grand Duke of Lithuania]] Jogaila with a lion, minted at the [[Vilnius Mint]] between 1386 and 1387]]
The Grand Duchy of Lithuania to which Jogaila succeeded as Grand Duke in 1377 was a political entity composed of two leading, but very different nationalities and two political systems: ethnic Lithuania in the north-west and the vast [[Ruthenia]]n territories of former [[Kievan Rus']], comprising the lands of modern Ukraine, Belarus, and parts of western Russia.<ref name="stone"/> At first, Jogaila—like his father—based his rule in the southern and eastern territories of Lithuania, while his uncle, [[Kęstutis]], the [[Duke of Trakai]], continued to rule the north-western region.<ref group=nb>Some historians have called this system a diarchy ({{Harvnb|Sruogienė-Sruoga|1987}}; {{Harvnb|Deveike|1950}}). However, Rowell suggests that the nature of this dual rule "...reflects political expediency; it certainly does not meet the formal definition of diarchy as 'rule by two independent authorities'...those two leaders were not equal: the grand duke in Vilnius was supreme" ({{Harvnb|Rowell|1994|p=68}}).</ref> Jogaila's succession, however, soon placed this system of dual rule under strain.<ref name="Bojtar"/>

At the start of his reign, Jogaila was preoccupied with unrest in the Lithuanian Rus' lands. In 1377–78, [[Andrei of Polotsk]], the eldest son of Algirdas, challenged Jogaila's authority and sought to become Grand Duke. In 1380, Andrei and another brother, [[Demetrius I Starshy|Dmitry]], sided with Prince [[Dmitri Donskoi|Dmitri of Moscow]] against Jogaila's alliance with emir [[Mamai]], de facto khan of the [[Golden Horde]].<ref name="plokhy"/> Jogaila failed to support Mamai, lingering in the vicinity of the battlefield, which led to Mamai's army's significant defeat at the hands of Prince Dmitri in the [[Battle of Kulikovo]]. The Muscovites' Pyrrhic victory over the Golden Horde, in the long term, signified, however, the beginning of a slow climb to power by the [[Grand Duchy of Moscow]], which became within a century the most serious rival and threat to the integrity, well-being and survival of Lithuania. However, in 1380 Muscovy was greatly weakened by tremendous losses suffered during the battle and thus, in the same year, Jogaila was free to begin a struggle for supremacy with Kęstutis.

[[File:Seal of Jogaila with his title as King in Lithuania (used in 1377-1386).jpg|thumb|upright=0.66|Seal of Jogaila with his title (in [[Latin]]) as King in [[Lithuania]], used in 1377–1386, before becoming the [[King of Poland]] in 1386]]
In the north-west, Lithuania faced constant armed incursions from the [[Teutonic Knights]]—founded after 1226 to fight and convert the pagan [[Baltic tribes]] of [[Old Prussians|Prussians]], [[Yotvingians]] and [[Lithuanians]]. In 1380, Jogaila concluded the secret [[Treaty of Dovydiškės]], directed against Kęstutis.<ref name="Bojtar"/> When Kęstutis discovered the plan, the [[Lithuanian Civil War (1381–1384)|Lithuanian Civil War]] began. He seized Vilnius, overthrew Jogaila, and pronounced himself grand duke in his place.<ref name="Jones"/> In 1382, Jogaila raised an army from his father's vassals and confronted Kęstutis near Trakai. Kęstutis and his son [[Vytautas]] entered Jogaila's encampment for negotiations but were tricked and imprisoned in the [[Kreva Castle]], where Kęstutis was found dead, probably murdered, a week later.<ref name="bojtár1"/> Vytautas escaped to the Teutonic fortress of [[Ordensburg Marienburg|Marienburg]] and was baptised there under the name Wigand.<ref name="Jones"/>

Jogaila formulated the [[Treaty of Dubysa]], which rewarded the Knights for their aid in defeating Kęstutis and Vytautas by promising Christianisation and granting them [[Samogitia]] west of the [[Dubysa]] river. However, when Jogaila failed to ratify the treaty, the Knights invaded Lithuania in the summer of 1383. In 1384, Jogaila reconciled with Vytautas promising to return his patrimony in Trakai. Vytautas then turned against the Knights, attacking and looting several Prussian castles.<ref name="Mick"/>

It is known that Jogaila, being ethnic Lithuanian in the male line, himself knew and spoke in the [[Lithuanian language]] with Vytautas, his cousin from the Gediminids dynasty.<ref>{{cite web |title=Ar perrašinėjamos istorijos pasakų įkvėpta Baltarusija gali kėsintis į Rytų Lietuvą? |url=https://www.15min.lt/naujiena/aktualu/istorija/ar-perrasinejamos-istorijos-pasaku-ikvepta-baltarusija-gali-kesintis-i-rytu-lietuva-582-456877 |last1=Pancerovas |first1=Dovydas |website=[[15min.lt]] |access-date=1 October 2014 |language=lt}}</ref><ref>{{cite web |last1=Statkuvienė |first1=Regina |title=Jogailaičiai. Kodėl ne Gediminaičiai? |url=https://www.15min.lt/naujiena/aktualu/istorija/jogailaiciai-kodel-ne-gediminaiciai-582-1056552 |website=15min.lt |access-date=9 November 2018 |language=lt}}</ref><ref name="Plikune"/> Also, during the [[Christianization of Lithuania#Christianization by Jogaila and Vytautas|Christianization of Samogitia]], none of the clergy, who came to [[Duchy of Samogitia|Samogitia]] with Jogaila, were able to communicate with the natives, therefore Jogaila himself taught the [[Samogitians]] about the [[Catholic Church|Catholicism]], thus he was able to communicate in the [[Samogitian dialect]] of the Lithuanian language.<ref>{{cite book |last1=Baronas |first1=Darius |title=Žemaičių krikštas: tyrimai ir refleksija |date=2013 |publisher=[[Lithuanian Catholic Academy of Science]] |location=[[Vilnius]] |isbn=978-9986-592-71-6 |pages=33–34 |url=https://www.lkma.lt/site/files/file/leidiniai/Zemaiciu_krikstas.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.lkma.lt/site/files/file/leidiniai/Zemaiciu_krikstas.pdf |archive-date=9 October 2022 |url-status=live |access-date=17 July 2021 |language=lt}}</ref> According to the Teutonic Order's testimonial, he could not read nor write, and had to listen to others reading for him.<ref name="Plikune">{{cite web |last1=Plikūnė |first1=Dalia |title=Kodėl Jogaila buvo geras, o Vytautas Didysis - genialus |url=https://www.delfi.lt/news/daily/lithuania/kodel-jogaila-buvo-geras-o-vytautas-didysis-genialus.d?id=76794153 |website=[[DELFI]] |access-date=19 May 2021 |language=lt}}</ref>