SIGISMUND III. (1566-1632), king of Poland and Sweden, son of John III, king of Sweden, and Catherine Jagiellonika, sister of Sigismund II. king of Poland, thus uniting in his person the royal lines of Vasa and Jagiello. Educated as a Catholic by his mother, he was on the death of Stephen Bathory elected king of Poland (Aug. 19, 1587) through the efforts of the Polish chancellor, Jan Zamoyski, and of his own aunt, Anne, queen dowager of Poland. Sigismund promised to maintain a fleet in the Baltic, to fortify the eastern frontier against the Tatars, and not to visit Sweden without the consent of the Polish diet. The articles of Kalmar regulated the future relations between Poland and Sweden, when Sigismund should succeed his father as king of Sweden. The two kingdoms were to be perpetually allied, but each of them was to retain its own laws. Sweden was also to enjoy her religion subject to such changes as a general council might make. During Sigismund's absence from Sweden that realm was to be ruled by seven Swedes, six to be elected by the king and one by Duke Charles, his Protestant uncle. Sweden, moreover, was not to be administered from Poland. The Poles first wished the cession of Estonia to Poland, but eventually the territorial settlement was postponed; and Sigismund was duly crowned at Cracow on Dec. 27, 1587.
From the first Sigismund was out of sympathy with the ma jority of his subjects. As a man of education and refinement, he was unintelligible to the szlachta, who regarded all artists and poets as either mechanics or adventurers. His reserve was called stiffness and his calm, haughtiness. Even Zamoyski who had placed him on the throne complained that the king was pos sessed by a dumb devil. He lacked, moreover, the tact and bon homie of the Jagiellos.
The first 23 years of the reign are the record of a constant struggle between Zamoyski and the king. In 1592 Sigismund mar ried the Austrian archduchess Anne, and a reconciliation was patched up between the king and the chancellor to enable the former to secure possession of his Swedish throne vacant by the death of his father John III. He arrived at Stockholm on Sept.
30, 1593 and was crowned at Upsala on Feb. 19, after he had consented to the maintenance of the "pure evangelical re ligion" in Sweden. On July 14, 1594 he departed for Poland leaving Duke Charles and the senate to rule Sweden during his absence. Four years later (July 1598) Sigismund was forced to fight for his native crown by the usurpation of his uncle, aided by the Protestant party in Sweden. He landed unopposed at Kalmar. After fruitless negotiations, Sigismund advanced with his army, but was defeated by the duke at Stangebro on Sept. 25. He never saw Sweden again, but refused to abandon his claims ; and this unfortunate obstinacy was to involve Poland in a whole series of unprofitable wars with Sweden.
In 1602 Sigismund wedded Constantia, the sister of his deceased first wife, an event which strengthened the hands of the Austrian party at court and still further depressed the chancellor. At the diet of 1605 Sigismund endeavoured to substitute a decision by a plurality of votes for unanimity in the diet. The opposition of Zamoyski nullified the effect of this salutary reform. His death, however, in the same year left his more ardent followers with out a check. From 16o6 to 1610 Poland was in an anarchical condition. On foreign affairs these disorders had a disastrous effect. Poland was unable to take the opportunity of breaking the power of the tsars, which the collapse of Muscovy had shaken. At the outbreak of the Thirty Years' War Sigismund prudently leagued with the emperor against the Turks and the Protestants. Sigismund died very suddenly in his 66th year, leaving two sons, Wladislaus and John Casimir, who succeeded him in rotation.
See Aleksander Rembowski, The Insurrection of Zebrzydowski (Pol.) (Cracow, 1893) ; Stanislaw Niemojewski, Memoires (Pol.) (Lemberg, 1899) ; Sveriges Historic, vol. iii. (Stockholm, 1880 ; Julian Ursyn Niemcewicz, History of the Reign of Sigismund III. (Pol.) (Breslau, 1836).