To balance the power of the great nobles Erik created a secondary nobility and intro duced the titles of count and baron into Swe den. A war with Russia, undertaken for the protection of the Teutonic order, resulted in the acquisition of Esthonia by Sweden ; but war having subsequently broken out with Den mark was, in the confusion caused by the Icing's insanity, ill-conducted, and resulted in repeated disasters to the Swedes. John III, the brother of Erik, succeeded him on his deposition. By the peace of Stettin with Denmark, 13 Dec. 1570, Sweden renounced her claims to Norway, and surrendered a large part of Gotland. in cluding the west coast to Denmark. This treaty was made with a view to a war with Russia. In this war the Swedes were success ful in foiling the designs of Ivan IV on Livo nia. Peace was concluded in 1582. John had married Catherine Jagellon, daughter of Sigis mund, king of Poland, and through her influ ence endeavored to restore the Catholic re ligion in Sweden. A formidable opposition arising, headed by his brother Charles, and the queen dying, he abandoned the project. Sigismund, his son, was, however, brought up in the Catholic faith, and in 1587 he was elected king of Poland under the title of Sigismund III; John died 1592. Charles, Duke of Suder mania, who held the regency in the absence of his nephew Sigismund, endeavored to de prive him of his crown on the ground of his religion, but on the return of Sigismund with an army he was compelled to relinquish the government to him. Sigismund, on receiving the crown, returned to Poland, and left his uncle Charles regent. Charles again attempted to seize the crown and defeated Sigismund in the battle of Stangbro (September 1598). The states now conferred on him the title of heredi tary prince, and insisted upon Sigismund send ing his son to Sweden to be educated in the evangelical faith. Failing to comply, he and his posterity were excluded from the crown, and in 1604 Charles was acicnowledged as king elect of the Swedes, Goths and Vandals, and his son, Gustavus Adolphus, was recognized as his successor. He took the title of Charles IX. From these events arose a war with Po land, which was not terminated by a permanent peace till 1660. Wars also with Denmark and Germany continued till the end of Charles' reign. Charles IX died 1611, and was suc ceeded by his son, Gustavus Adolphus, then en gaged in conducting the war with Denmark. One of the first acts of Gustavus was to se lect as his chancellor Alex Oxenstiern, who became one of the first statesmen of Europe. Failing to make peace with Denmark, Gustavus took the field in person, and nearly lost his life in the battle of Widsji; but in 1613 he suc ceeded through the mediation of England in making peace. The Russian throne was then vacant. The Swedes and Poles each set up candidates for it, Charles Philip, brother of Gustavus and Ladislaw, son of Sigismund. Both had invaded the country and made ex tensive conquests and Gustavus granted favor able tertns to Denmark that he might turn his attention to this quarter. Michael Romanoff, elected in 1613, was compelled to make peace with Sweden by the cession of all his Baltic provinces; and Sweden, which notwithstanding internal troubles had been advancing in politi cal importance since the time of Gustavus I, now became the leading power of the North. The war of succession with Poland still con tinued and in 1621 Gustavus turned his arms against that country and captured Riga. The war continued for nine years, and was con cluded by the six years' truce of Altmark in 1629. Gustavus retained four frontier towns of East Prussia.
Sweden was now about to take for the first time a leading part in the affairs of Europe. Gustavus had been watching with anxiety the course of events in Germany, and had de terrnined to interfere on behalf of the interests of religion and the political rights of the Prot estant princes. (For the events of this war and the effects of the intervention of Sweden in the affairs of Europe see GUSTAVUS ; PaussiA; RICHELIEU ; THIRTY YEARS' WAR, and other articles). The body of Gustavus, who fell at
the battle of Liitzen, was brought back to Swe den in 1632, and his daughter Christina was recognized as his successor. She was a minor, and the management of affairs devolved upon the Chancellor Oxenstiern. He confirmed his alliance with the German rulers, and made ar rangements to prosecute the war with vigor. His power continued absolute till 1644, during which time the war in Germany continued. At the beginning of this year a war broke out with Denmark, provoked by the scheming of the queen-mother, who was jealous of the power of Oxenstiern. Denmark was sud denly invaded by Torstenson. Christina as sumed the reins of government on 5 Dec. 1644, her 18th birthday. The peace party now prevailed, and the treaty of Bromsebro was concluded with Denmark, which ceded to Swe den the greater part of her possessions in Gotland, and exempted Swedish vessels from Sound and Belt dues. The peace of West phalia, 24 Oct. 1648, gave Sweden western Pom erania, the duchy of Bremen and other acquisi tions in Germany, with a seat and triple vote in the diet.
The reign of Christina began under favor able auspices. She had received a masculine education, and showed great attention to busi ness and determination in supporting her views. Contrary to the advice of Oxenstiern she ex erted herself to promote peace both with Den mark and Germany. She patronized learning, and drew many distinguished men to her court; but she was extravagant in her expenditure, licentious in her behavior, and soon brought herself into inextricable difficulties by the pro fusion with which she lavished the crown do mains on worthless favorites. In these circum stances she renounced the crown in 1654 in favor of her cousin Charles Gustavus, son of the count palatine, professed the Catholic re ligion, and after an extraordinary career died at Rome in 1689. The short reign of Charles X was distinguished by some brilliant military enterprises, which extended to Poland, Prussia, Russia and Denmark. In January 1658 he crossed the sea on' the ice, and occupying the island of Fiinen without resistance, advanced to Copenhagen. By the mediation of England and France peace was concluded at Roeskilde, 8 March 1658, Denmark surrendering the re mainder of her possessions in Gotland. Charles, however, had set his heart on the conquest of Denmark, and was not long in recommencing operations against that country. He died sud denly on 13 Feb. 1660, leaving a son, Charles XI, only four years of age. A council of re gency was appointed, which soon concluded peace with Poland, the emperor and the elector of Brandenburg. Peace with Russia was not concluded till 1661. Sweden formed an alliance with England against Holland in 1665, and took part in the triple alliance against France in 1668. The common policy of Sweden was to ally herself with France, and her change of policy was due to the failure of French subsi dies. By the treaty of Stockholm, 14 April 1672, she agreed to assist France if attacked by any German power during her war with Hol land. In consequence of this treaty the Swedes invaded Brandenburg in 1674. They were de feated by the elector at Fehrlallin, 28 June 1675. After this victory Denmark entered into a league with the elector against Sweden. In the hotly contested war which ensued Sweden was defeated by the elector on land and by the Danes at sea, but her ally was victorious, and Louis XIV compelled the elector by the treaty of Saint Germain-en-Laye to restore to Sweden all her German possessions except a district beyond the Oder, and by the treaty of Fon tainebleau Christian V engaged to restore all his conquests to Sweden. Peace was concluded on these terms between Sweden and Denmark at London, 26 Sept. 1679.