Sigismund III (June 20, 1566 – April 30, 1632) was King of Poland and Grand Duke of Lithuania from 1587 to 1632 and, as Sigismund III, King of Sweden and Grand Duke of Finland from 1592 to 1599. He was the first Polish sovereign from the House of Vasa.
A religious zealot, he imposed Roman Catholic doctrine across the vast realm, and his crusades against neighbouring states marked Poland’s largest territorial expansion. As an enlightened despot, he presided over an era of prosperity and achievement, further distinguished by the transfer of the country’s capital from Kraków to Warsaw.
Born on June 20, 1566 at Gripsholm Castle, Sigismund was the second child and only son of Catherine Jagiellon and Grand Duke Johan of Finland (future King Johan III of Sweden) who was the son of King Gustaf I of Sweden and his second wife Margaret Leijonhufvud.
Johan and Catherine were held prisoner at Gripsholm since 1563 when Johan staged a failed rebellion against his deranged brother Eric XIV of Sweden.
Although Protestant Christians were a growing political wing in Poland at the time, Sigismund was raised as a Roman Catholic. His mother Catherine was the daughter of Polish king, Sigismund I the Old and Bona Sforza of Milan, all of whom where practicing Catholics.
Sigismund I the Old was King of Poland and Grand Duke of Lithuania from 1506 until his death in 1548. He was nicknamed “the Old” in later historiography to distinguish him from his son and successor, Sigismund II of Poland.
Sigismund’s older sister Isabella died aged two in 1566. His younger sister Anna was a Lutheran, but the close relationship between the two siblings remained unchanged until her death in 1625.

In October 1567 Sigismund and his parents were released from prison at the request of his uncle Carl. In January 1569, Eric XIV was deposed and Sigismund’s father ascended the throne of Sweden as King Johan III.
Sigismund maintained good relations with his father despite Johan’s second marriage to Gunilla Bielke, a Protestant noble lady of lower status and Catherine’s former maid of honour. In 1589, Sigismund’s half-brother Johan, the future Duke of Östergötland, was born.
As a child, Sigismund was tutored in both Polish and Swedish, thus making him bilingual. He was also proficient in German, Italian, and Latin. Catherine ensured that her son was educated in the spirit of Catholicism and Polish patriotism; the young prince was made aware of his blood connection to the Jagiellonian dynasty which ruled Poland in its finest period for two hundred years.
In 1587 Sigismund stood for election to the Polish throne after the death of Stephen Báthory. His candidacy was secured by Queen Dowager Anna and several elite magnates who considered him a native candidate as a descendant of the Jagiellons, though the election was openly questioned and opposed by the nobles politically associated with the Zborowski family.
With the blessing of primate Stanisław Karnkowski and strong support from other people of influence he was duly elected ruler of the Polish–Lithuanian Commonwealth on August 19, 1587. His official name and title became “by the grace of God, Sigismund III King of Poland, grand duke of Lithuania, ruler of Ruthenia, Prussia, Masovia, Samogitia, Livonia and also hereditary king of the Swedes, Goths and Wends”; the latter titles being a reference to the fact that he was already the Crown Prince of Sweden, and thus would lawfully succeed to the throne of Sweden upon the death of his father.
When his father died, Sigismund was granted permission by the Polish Diet to claim the Swedish crown, which he had inherited from his father. The Swedes, who previously declared Johan III a Catholic conspirator and traitor, became lenient when the new monarch pledged to respect Lutheranism as the country’s new state religion.
On 31 May 1592 Sigismund married his first wife Anne of Austria (1573–1598), daughter of Archduke Charles II of Austria and his wife Maria Anna of Bavaria. She was well received in Poland, despite being a Habsburg. Certain leading magnates were initially opposed to the marriage.
Queen Anne died from a puerperal fever at childbirth along with the baby boy on February 10, 1598 in Warsaw. Following her death, Sigismund was in deep mourning; he expressed sorrow in private letters to his mother-in-law Maria Anna of Bavaria, and isolated himself from subjects.
Sigismund was expected to marry Anna of Tyrol in 1603, however Emperor Rudolf II did not give his consent. Instead, on December 11, 1605 he wedded Constance of Austria (1588–1631), Anne’s younger sister. The match was condemned by nobles and clerics who previously opposed Anne and the Habsburg alliance; the match was savagely described as “incestuous” since he married his dead wife’s sister.

Sigismund was crowned at Uppsala on February 19, 1594, As King Sigismund (no ordinal number) of Sweden but his promise to uphold the Protestant faith in Sweden began on shaky ground, as demonstrated by the presence of a papal nuncio in the royal procession. Tensions grew following his coronation.
Sigismund remained a devout Roman Catholic and left Sweden abruptly, which made the Swedes sceptical of their new ruler.
Sigismund attempted to hold absolute power in all his dominions and frequently undermined parliament. He suppressed internal opposition, strengthened Catholic influence and granted privileges to the Jesuits, whom he employed as advisors and spies during the Counter-Reformation.
On August 4, 1594 Sigismund decreed that the Swedish parliament (riksdag) had no right to function without royal consent. Despite this, Carl summoned a parliament at Söderköping in autumn of 1595, at which he declared himself regent and head of government, who would govern Sweden reciprocally with the Privy Council during the king’s absence from the realm.
Sigismund actively interfered in the affairs of neighbouring countries; his invasion of Russia during the Time of Troubles resulted in brief control over Moscow and seizure of Smolensk.
After a lengthy Civil War in Sweden King Sigismund was officially deposed from the throne of Sweden by a riksdag held in Stockholm on July 24,1599. He was given six (or twelve depending on source) months to send his son, Prince Ladislaus (Władysław) Vasa, to Sweden as his successor, under the condition that the boy would be brought up in the Protestant faith.
In February 1600, Duke Carl summoned the Estates of the Realm to Linköping. Since Sigismund had not provided a reply, the Estates elected Duke Carl as king apparent, however he would not become Carl IX until his coronation four years later. During the winter and spring of 1600, Carl also occupied the Swedish part of Estonia, as the castle commanders had shown sympathies towards Sigismund.
Sigismund’s army also defeated the Ottoman forces in southeastern Europe, which hastened the downfall of Sultan Osman II. However, the Polish–Swedish conflict had a less favourable outcome. After a series of skirmishes ending in a truce, King Gustaf II Adolph of Sweden (his first cousin and the son and successor of his uncle King Carl IX of Sweden) launched a campaign against the Commonwealth and annexed parts of Polish Livonia.
Towards the end of his reign, Sigismund withdrew altogether from politics and devoted himself exclusively to family matters and his interests in performing arts.
Little is known about the king’s wellbeing at the time suggesting that he was in good health. However, in his last days he became bedridden due to gout and joint pain, an affliction which was likely inherited from his grandfather Sigismund the Old. His uncle, Sigismund II Augustus of Poland, also suffered from long-term arthritis.
Shortly after the unexpected death of his second wife, Constance, Sigismund fell dangerously ill and experienced mental problems, notably he was struck with severe depression.
The king sensed that death is near and ordered an immediate assembly of nobles, which convened on 1 April. The so-called ‘extraordinary parliament’ (sejm ekstraordynaryjny) secured the candidacy and election of his son, Ladislaus, to the throne. On Easter Sunday he participated in final prayers, whilst being supported by his sons to prevent him from collapsing.

At eight in the morning on April 25, Kasper Doenhoff, a courtier in charge of opening curtains in the royal bedchamber and greeting the monarch, did not hear a response. Unable to see at a distance he approached Sigismund whose face was paralyzed from a stroke. Hours later he briefly recovered his speech and murmured “there is no cure against the will [power] of death”.
On April 28, Sigismund’s bed was surrounded by his courtiers and the Jesuit priests, who performed exorcism-like prayers. It was his wish that the court be witness to his demise, as interpreted in the words “vanitas vanitatis”, Latin for ‘all is vanity’.
After days of suffering, Sigismund passed away at Warsaw’s Royal Castle at approximately 2:45 am (02:45) on April 30, 1632.
Sigismund remains a controversial figure in Poland. One of the country’s most recognisable monarchs, his long reign coincided with the Polish Golden Age, the apex in the prestige, power and economic influence of the Polish–Lithuanian Commonwealth.