Charles IX (king of Sweden)
Charles IX, 1550–1611, king of Sweden (1604–11), youngest son of Gustavus I. He was duke of Södermanland, Närke, and Värmland before his accession. During the reign of his brother, John III (1568–92), he opposed John's leanings toward Catholicism. After John's death he acted as regent, summoned (1593) an assembly of clergy and nobles to Uppsala, and had it establish Lutheranism as the state religion. This measure was passed in anticipation of the arrival (1594) of John III's Catholic son and heir, King Sigismund III of Poland, who was obliged to pledge himself to uphold Protestantism in Sweden as a condition for his coronation. Sigismund left Sweden in the same year, and Charles summoned the Riksdag, was made regent against the king's wishes, and ousted all Catholic officials. The Swedish nobles were loyal to Sigismund, but the people supported Charles. Sigismund landed an army at Kalmar (1598), was defeated by Charles at Stangebro, and was deposed by the Riksdag in 1599. To consolidate his power Charles had most of his opponents executed, but he refused to accept the Swedish crown until Sigismund's brother, John, renounced it in 1604. In 1600 he invaded Livonia and thus began the long Polish-Swedish wars that ended only with the Peace of Oliva in 1660. Charles's claim to Lapland involved him in the unsuccessful Kalmar War (1611–13) with Christian IV of Denmark. He died before the conclusion of the war and was succeeded by his son, Gustavus II.