[1] The personal union between the Kingdom of Poland and the Grand Duchy of Lithuania (converted in 1569 with the Treaty of Lublin into the Polish–Lithuanian Commonwealth) is the reason for the common appellation "Poland–Lithuania" in discussions about the area from the Late Middle Ages onward.

In Polish, the dynasty is known as Jagiellonowie and the patronymic form: Jagiellończyk; in Lithuanian it is called Jogailaičiai, in Belarusian Яґайлавічы (Jagajłavičy), in Hungarian Jagelló, and in Czech Jagellonci, as well as Jagello or Jagellon in Latin.

As a result of the Union of Krewo he then converted to Christianity and married the 11-year-old Queen Hedwig of Poland (daughter of King Louis I of Hungary from the Angevins Dynasty).

[citation needed] In 1385 the Union of Krewo was signed between Queen Hedwig of Poland and Jogaila, the Grand Duke of Lithuania, the last pagan state in Europe.

Uniquely in Europe, the union connected two states geographically located on the opposite sides of the great civilizational divide between the Western or Latin, and the Eastern or Byzantine worlds.

[7] The intention of the Union was to create a common state under Ladislaus II Jagiełło, but the Polish ruling oligarchy's idea of incorporation of Lithuania into Poland turned out to be unrealistic.

Geographic consequences of the dynastic union and the preferences of the Jagiellonian kings accelerated the process of reorientation of Polish territorial priorities to the east.

[8] The political influence of the Jagiellonian kings was diminishing during this period, which was accompanied by the ever-increasing role in central government and national affairs of landed nobility.

The Jagiellonian Era is often regarded as a period of maximum political power, great prosperity, and in its later stage, the Golden Age of Polish culture.

The Great War of 1409–1411, precipitated by the Lithuanian uprising in the Order controlled Samogitia, included the Battle of Grunwald (Tannenberg), where the Polish and Lithuanian-Rus' armies completely defeated the Teutonic Knights.

In 1434 the old monarch died and his minor son Ladislaus was crowned; the Royal Council led by Bishop Oleśnicki undertook the regency duties.

Their leader Spytek of Melsztyn was killed during an armed confrontation in 1439, which allowed Oleśnicki to purge Poland of the remaining Hussite sympathizers and pursue his other objectives without significant opposition.

Throughout Casimir's youth, Bishop Zbigniew Oleśnicki was his mentor and tutor; however, the cleric felt a strong reluctance towards him, believing that he would be an unsuccessful monarch following Ladislaus' death.

[3][18][19][20] In 1445, Casimir IV Jagiellon, already being the Grand Duke of Lithuania, was asked to also assume the Polish throne vacated by the death of his brother Ladislaus III (killed at the Battle of Varna in 1444).

A conflict with the pope and the local Church hierarchy over the right to fill vacant bishop positions Casimir IV Jagiellon also resolved in his favor.

In addition to land warfare, naval battles had taken place, where ships provided by the City of Danzig (Gdańsk) successfully fought Danish and Teutonic fleets.

The Turkish controlled Crimean Tatars raided the eastern territories in 1482 and 1487, until they were confronted by King John Albert, Casimir's son and successor.

[24] In 1506 he was succeeded by Sigismund I the Old (Polish: Zygmunt I Stary, Lithuanian: Žygimantas Senasis) in both Poland and Lithuania, as the political realities were drawing the two states closer together.

[25] Bona's sway over the king and the magnates, her efforts to strengthen the monarch's political position, financial situation, and especially the measures she took to advance her personal and dynastic interests, including the forced royal election of the minor Sigismund Augustus in 1529 and his premature coronation in 1530, increased the discontent among szlachta activists.

The derisive name was coined by the magnates, who for the most part supported the King and claimed that the "war's" only effect was the near-extinction of the local chickens, eaten by the nobles gathered for the rebellion at Lwów, in Lesser Poland.

[26] Sigismund II possessed to a high degree the tenacity and patience that seem to have characterized all the Jagiellons, and he added to these qualities a dexterity and diplomatic finesse.

Unsuccessful and debilitating beginning of the Livonian War for the Grand Duchy of Lithuania and Lithuanian nobility's desire for equal rights with the Polish nobility resulted in childless Sigismund II's possibly the most striking memorial—the Union of Lublin, which united Poland and Lithuania with equal rights into the Polish-Lithuanian Commonwealth—the "Republic of the Two Nations" (Polish: Rzeczpospolita Obojga Narodów, Lithuanian: Abiejų Tautų Respublika).

As was the case with other European nations, the Renaissance inspiration came in the first place from Italy, a process accelerated to some degree by the marriage of Sigismund I to Bona Sforza.

While the pioneering Polish humanists, greatly influenced by Erasmus of Rotterdam, accomplished the preliminary assimilation of the antiquity culture, the generation that followed was able to put greater emphasis on the development of native elements, and because of its social diversity, advanced the process of national integration.

The Academy of Kraków and Sigismund II possessed well-stocked libraries; smaller collections were increasingly common at noble courts, schools and the households of townspeople.

In 1515, during a congress in Vienna, a dynastic succession arrangement was agreed to between Maximilian I, Holy Roman Emperor and the Jagiellon brothers, Vladislaus II of Bohemia and Hungary and Sigismund I of Poland and Lithuania.

It was supposed to end the Emperor's support for Poland's enemies, the Teutonic and Russian states, but after the election of Charles V, Maximilian's successor in 1519, the relations with Sigismund had worsened.

Stephen Zápolya, the archbishop Tamás Bakócz and George Szatmári continued with the Turkish war plans and tried then to maintain the Kingdom that fell in a severe economical crisis after Matthias's death.

This was disastrous for Louis' kingdom; without the strategically important cities of Belgrade and Šabac, Hungary, including Buda, was open to further Turkish conquests.

At one point, the Jagiellonians established dynastic control also over the kingdoms of Bohemia and Hungary (from 1490 onwards), with Vladislaus Jagiello whom several history books call Vladisla(u)s II.