John ascended to the Polish throne in 1492, and his younger brother Alexander was elected Grand Duke of Lithuania by an independent Lithuanian assembly, thus temporarily breaking the personal union between the two nations.

To secure his succession against the Piast princes from the Duchy of Masovia, he dispatched an army to the electoral proceedings, which alienated the higher nobles and magnates.

John Albert remains a largely forgotten and overlooked figure in the history of Poland, his relatively short reign ended in a major military setback, and he was criticised during his lifetime for embracing absolutism as well as attempting to centralise the government.

[10] John's father was reluctant to accept the Polish crown and only did so when his opponents, Bolesław IV of Warsaw and Frederick II, Elector of Brandenburg, strengthened their efforts.

[14] This changed when George of Poděbrady pledged to make Vladislaus his heir in neighbouring Bohemia on the condition that Casimir IV negotiated a peace treaty with Matthias Corvinus of Hungary.

[20][21] In spite of the conflict, the bond between the two siblings remained unhindered,[22] and Vladislaus made John the Duke of Głogów for life to satisfy his ambition.

[24] In September 1467, chronicler and historian Johannes Longinus (Polish: Jan Długosz) was entrusted by Casimir with tutoring the royal children, including young John.

[26] During their childhood, John and his brother Alexander were instructed to regularly visit the tombs of past sovereigns in an attempt to strengthen their allegiance to Poland.

[29] The Italian humanist and diplomat Filippo Buonaccorsi, known as Callimachus or Kallimach, exercised immense authority and influence over John in his early years and during his reign.

[38] Lithuanian dignitaries were satisfied with the proposition; a cluster of Polish nobility wished to continue the personal union between the two countries and initially opted for Alexander.

[46][47] Janusz's candidacy was endorsed by a strictly covert contingent of conservatives, whose intention was to restore the ancient House of Piast on the Polish throne.

[51] In the end, it was Frederick's personal intervention that secured the crown for John, who was unanimously proclaimed king by an oral ballot amongst the shrieks of nobles on 27 August 1492.

[58] Constitutionalism and parliamentary tendencies in Poland date back to the Late Middle Ages, when Louis I issued the 1374 Privilege of Koszyce, granting the nobility concessions (tax reductions) and prerogatives in return for favours or military support.

[61] A major breakthrough came in 1454, when John's father, Casimir, approved the Statutes of Nieszawa; which obligated the monarch to seek advice from the gentry and sejmiks (regional land councils) before taking action.

[73] The delay may have been attributed to the extensive distance covered (approximately 40–50 kilometres a day), as well as to the festivities and welcoming ceremonies in each town his royal cortège passed.

[79] In the same year, the Jewish inhabitants, jointly with the city council representatives and burghers, lodged their complaints before John Albert in a private audience.

[82] In 1495, John issued an edict whereby he expelled Jews from Kraków and forcibly relocated them in the adjacent township of Kazimierz, which became one of Poland's primary centres of Judaism.

[83] Chroniclers from the period make no mention of an expulsion; Marcin Kromer suggested that the relocation was in part voluntary and for the benefit of the Jews who faced persecution from Christians.

[87] When Duke Janusz II died heirless in February 1495, his brother Konrad hurried to secure his disputed succession by sending out troops to fortify Masovian castles.

[88] He failed in deterring Polish ambitions; John soon assembled a small force that marched into Masovia and occupied the ecclesiastical city of Płock, the region's primary bishopric.

[92] John desired to pose as the champion of Christendom against the Ottoman Turks, whilst regaining lost ports near the Black Sea (Cetatea Albă and Chilia)[93][94] and strengthening suzerainty over Moldavia.

[101] In August 1497, tax levies equivalent to 25 per cent of ecclesiastical incomes were demanded from the clergy by Cardinal Frederick Jagiellon to support his brother.

[127] Fearing a retaliatory attack by the Moldavians or the Ottoman Empire, John ordered the construction of new defensive fortifications; including what became one of Poland's most recognisable monuments, the Kraków Barbican.

[128] The ceding of Prussia to Poland as a royal dependency in the aftermath of the Thirteen Years' War (1454–1466) caused great animosity between the Teutonic State and the Polish Crown, even when the two were allies.

Maximilian I, Holy Roman Emperor, permitted Friedrich to aid Poland when called, but insisted that he refrains from searing oath of allegiance to the Polish king, instead maintaining "friendly" and "neighbourly" relations.

[135] When Maximilian denounced the Peace of Thorn, asserting that neither the Empire nor the Holy See approved it, John mobilised a force with heavy artillery and set out to Toruń in 1501 where the accords were initially signed.

[137] Fearing a major regional conflict, George, Duke of Saxony, and John's brother-in-law by marriage to Barbara Jagiellon, entrusted the Catholic Bishop of Meissen with mediating between the Poles and the Teutonic Knights.

[146] From 1502 to 1505, Francesco Fiorentino created an Early Renaissance niche and archway, based on Leonardo Bruni's tomb at the Basilica of Santa Croce in Florence.

[155] This greatly hindered the development of Polish towns and cities in comparison with their Western European counterparts, and resulted in low urbanisation rates across the country.

[158] Maciej Miechowita writes that he "indulged in [sexual] pleasures and desires like a warrior",[159] and Marcin Kromer noted his "insistence on carnal and affectionless love".