The war against Sigismund () was a war between Duke Charles, later known as King Charles IX of Sweden, and Sigismund, who was at the time the king of both Sweden and the Polish–Lithuanian Commonwealth (that is, the King of Poland and the Grand Duke of Lithuania). Lasting from 1598 to 1599, it is also called the War of Deposition against Sigismund, since the focus of the conflict was the attempt to depose the latter from the throne of Sweden. The war eventually resulted in the deposition of Sigismund (with Duke Charles taking over the government and later also acceding to the throne), the dissolution of the Polish-Swedish Union, and the beginning of an eleven-year war. Background When Stephen Báthory died in 1586, Sigismund Vasa, son of King John III and Catherine Jagiellonica, was elected king of the Polish–Lithuanian Commonwealth in an attempt to continue the Polish–Swedish alliance, the original purpose being to confront Ivan IV "the Terrible" of Russia. Sigismund had sworn to cede Estonia to the Commonwealth. When King John III died in 1592 his son Sigismund, King of Poland since 1587, acceded to the Swedish throne. Then conflicts arose. Duke Charles, the only living son of Gustav Vasa, did not approve the accession of Sigismund, his nephew and a Catholic, to the government of a realm that could just as well be his. After Sigismund had been crowned King of Sweden on February 19, 1594, he decided that no Parliaments (riksdagar) could be summoned without the King's consent. Despite this, Charles summoned a Parliament at Söderköping in autumn 1595, at which he managed to get his will through. The Duke was appointed Regent with "the advice of the Council", meaning that he was to govern Sweden together with the Privy Council during the King's absence from the Realm. Soon afterwards, the nobility of Finland, led by the Sigismund-appointed Governor, Klaus Fleming, rejected these decisions. They sympathised with the King and considered Charles a rebel. As a counterattack, Charles instigated a rebellion against Fleming, the Cudgel War, among the farmers in Ostrobothnia. Fleming managed to quell the revolt but died in April 1597. Roughly at the same time, a letter arrived from Sigismund's headquarters in Poland stating that he would not accept Charles as regent. The Duke then used a tactic which his father had employed, namely to resign from office. However, the response was not what Charles