Charles XI or Carl (Swedish: Karl XI; 4 December [O.S. 24 November] 1655 – 15 April [O.S. 5 April] 1697) was King of Sweden from 1660 until his death, in a period of Swedish history known as the Swedish Empire (1611–1721).
He was the only son of King Charles X Gustav of Sweden and Hedwig Eleonora of Holstein-Gottorp. His father died when he was four years old, so Charles was educated by his governors until his coronation at the age of seventeen. Soon afterward, he was forced out on military expeditions to secure the recently acquired dominions from Danish troops in the Scanian War. Having successfully fought off the Danes, he returned to Stockholm and engaged in correcting the country's neglected political, financial, and economic situation. He managed to sustain peace during the remaining 20 years of his reign. Changes in finance, commerce, national maritime and land armaments, judicial procedure, church government, and education emerged during this period. Charles XI was succeeded by his only son Charles XII, who made use of the well-trained army in battles throughout Europe.
The fact that Charles was crowned as Charles XI does not mean that he was the 11th king of Sweden who had the name Charles. His father's name (as the 10th) was due to his great-grandfather, King Charles IX of Sweden (1604–1611), having adopted his own numeral by using a mythological History of Sweden. That ancestor was actually the third King Charles. The numbering tradition thus begun still continues, with the present king of Sweden being Carl XVI Gustaf. He has also once been called Charles IV.