[2] Some time after 1553, Báthory was captured by the Turks, and after Ferdinand I refused to pay his ransom, joined the opposing side, supporting John II Sigismund Zápolya in his struggle for power in the Eastern Hungarian Kingdom.

[4] In 1572, the throne of the Polish–Lithuanian Commonwealth, at the time the largest and one of the most populous states in Europe, was vacated when King Sigismund II Augustus died without heirs.

[4] On 12 December 1575, after an interregnum of roughly one and a half years, primate of Poland Jakub Uchański, representing a pro-Habsburg faction, declared Archduke Maximilian III as the new monarch.

[8] After a heated discussion, it was decided that Anna Jagiellon, sister of the former King Sigismund II Augustus, should be elected 'king' and marry Stephen Báthory.

[a][9][14] On 29 May 1580, a ceremony was held in the Vilnius Cathedral during which bishop Merkelis Giedraitis presented Báthory a decorated sword and a hat adorned with pearls (both were sanctified by Pope Gregory XIII himself), while this ceremony manifested the sovereignty of the Grand Duchy of Lithuania and had the meaning of elevation of the new Grand Duke of Lithuania, this way ignoring the stipulations of the Union of Lublin.

[14] Maximilian's sudden death improved Báthory's situation, but the city of Danzig (Gdańsk) still refused to recognize his election without significant concessions.

[22][23] In exchange for some of Danzig's demands being favorably reviewed, the city recognised Báthory as ruler of Poland and paid the sum of 200,000 zlotys in gold as compensation.

[21][23] Tying up the administration of the Commonwealth's northern provinces, in February 1578 he acknowledged George Frederick as the ruler of Duchy of Prussia, receiving his feudal tribute.

[21] After securing control over the Commonwealth, Báthory had a chance to devote himself to strengthening his authority, in which he was supported by his chancellor Jan Zamoyski, who would soon become one of the king's most trusted advisers.

[21][24] In exchange, the Sejm allowed him to raise taxes and push a number of reforms strengthening the military, including the establishment of the piechota wybraniecka, an infantry formation composed of peasants.

[25] In his last years, Báthory, with Pope Gregory XVIII's approval, made a plan with Antonio Possevino for the liberation of Ottoman Hungary by a well organized (mostly Polish) Christian army, and the creation of a strong and independent Hungarian-Polish union under his rule.

[30] The treaty was favorable to the Commonwealth, as Ivan ceded Polatsk, Veliz and most of the Duchy of Livonia in exchange for regaining Velikiye Luki and Nevel.

[24][31] In external politics, Báthory was considering another war with Russia, but his plans were delayed due to the lack of support from the Sejm, which refused to pass the requested tax raises.

[25] He became a recurring character in Polish poetry and literature and featured as a central figure in poems, novels and drama by Jakub Jasiński, Józef Ignacy Kraszewski, Julian Ursyn Niemcewicz, Henryk Rzewuski and others.

[34][35] A statue of Báthory by Giovanni Ferrari was raised in 1789 in Padua, Italy, sponsored by the last king of the Commonwealth, Stanisław August Poniatowski.

Many nobles took his behavior in the Zborowski affair and his domestic policies as indicating an interest in curtailing the nobility's Golden Freedoms and establishing an absolute monarchy.

[34] He was remembered for his military triumphs and praised as an effective ruler by many, including John Baptist Albertrandi, Jerzy Samuel Bandtkie, Michał Bobrzyński, Józef Szujski and others.

[34] During the interwar period in the Second Polish Republic he was a cult figure, often compared - with the government's approval - to the contemporary dictator of Poland, Józef Piłsudski.

[34] After the Second World War, in the communist People's Republic of Poland, he became more of a controversial figure, with historians more ready to question his internal politics and attachment to Hungary.

[34] Nonetheless, his good image remained intact, reinforced by the positive views of a popular Polish historian of that period, Paweł Jasienica.