Charles XIII of Sweden Charles XIII & II also Carl , ( Stockholm , 7 October 1748 – Stockholm , 5 February 1818 ) , was King of Sweden ( as " Charles XIII " ) from 1809 and King of Norway ( as " Charles II " ) from 1814 until his death . He was the second son of King Adolf Frederick of Sweden and Louisa Ulrika of Prussia , sister of Frederick II of Prussia . Though known as King Charles XIII in Sweden , he was actually the seventh Swedish king by that name , as Charles IX ( reigned 1604 – 1611 ) had adopted his numeral after studying a fictitious history of Sweden . Life and politics . Prince Charles was appointed grand admiral when he was but few days old . He was described as a good dancer at the amateur theatre of the royal court . Reportedly he was not very close to his mother ; the Queen preferred her youngest children , Sophie Albertine and Frederick Adolf . Charles was , however , described as close to his brother Gustav during their childhood . In 1772 he cooperated in the revolutionary plans of his elder brother , King Gustav III of Sweden and as a sign of recognition , was appointed Duke of Södermanland . Charles was early the object of his mother ' s plans to arrange political marriages for her children . Initially , he was to be married to Philippine of Brandenburg - Schwedt according to his mother ' s wishes , but the government refused to issue negotiations because of the costs . After the coup d ' état which introduced absolute monarchy in 1772 , his brother Gustav III arranged a marriage between Charles and his cousin Hedwig Elizabeth Charlotte of Holstein - Gottorp . They lived de facto separate private lives and both had extramarital affairs . Charles was known for his " harem " of mistresses , of which the most notable were Augusta von Fersen , Charlotte Eckerman , Charlotte Slottsberg , who also had influence over him , and Mariana Koskull . He unsuccessfully courted Magdalena Rudenschöld , who refused him , after which she was treated with what has been regarded as vindictiveness during the Armfelt conspiracy . After the late 1790s , his health deteriorated by a series of rheumatic attacks , his relationship to his consort improved and she gained more influence over him . Charles was described as dependent and easily influenced by others , and his many affairs gave him the reputation of being a libertine . He was very interested in the supernatural , secret societies and mysticism . It is said that he was one of the best clients of the celebrated fortune teller Ulrica Arfvidsson and even asked her for political advice , and he also favoured the medium Henrik Gustaf Ulfvenklou , who also exercised great influence over the duke . He was also a member of the Freemasons and in 1811 founded the Order of Charles XIII , a Swedish order of chivalry awarded only to Protestant Freemasons . Charles was given several official tasks during his period as duke . In 1777 , he served as regent during Gustav III ' s stay in Russia , in 1780 he served as formal chief commander during the King ' s stay in Spa . On the outbreak of the Russo - Swedish War of 1788 he served with distinction as admiral of the fleet , especially at the battles of Hogland ( 7 June 1788 ) and Öland ( 26 July 1789 ) . On the latter occasion he would have won a signal victory but for the unaccountable remissness of his second - in - command , Admiral Liljehorn . In 1785 , he was offered the Dukedom of Courland by the nobility of the Duchy and given the support of Gustav III . but the plans never materialized . Charles was in close connection to the opposition against Gustav III , and it is debated whether he knew of and supported the plans to assassinate the King . On the assassination of Gustav III in 1792 , Charles acted as regent of Sweden till 1796 on behalf of his nephew , King Gustav IV , who was a minor when his father was shot in the Stockholm opera . The de facto regent , however , was in fact Gustaf Adolf Reuterholm , whose influence over him was supreme . These four years have been considered perhaps the most miserable and degrading period in Swedish history ; an Age of Lead succeeding an Age of Gold , as it has well been called , and may be briefly described as alternations of the fantastic jacobinism and the ruthless despotism . On the coming of age of Gustav IV Adolf of Sweden in November 1796 , the duke ' s regency ended . In 1803 , the Boheman affair caused a severe conflict between Gustav IV Adolf and the ducal couple . The mystic Karl Adolf Boheman ( 1764 – 1831 ) had been introduced to the couple by Count Magnus Stenbock in 1793 and gained great influence by promising to reveal scientific secrets about the occult . Boheman inducted them into a secret society and founded what he described as a branch of the Freemasons in 1801 , where both sexes where accepted as members , and to which the Counts and Countesses Ruuth and Brahe as well as the mother of the queen were introduced . Boheman was arrested upon an attempt to recruit the monarch , who accused him of revolutionary agendas and expelled him . The ducal couple were exposed in an informal investigation by the monarch , and the duchess was questioned in the presence of the royal council . In 1808 , he was again chief commander during Gustav IV Adolf ' s stay in Finland . On 13 March 1809 , those who had dethroned Gustav IV Adolf appointed him regent , and he was finally elected king by the Riksdag of the Estates . But by this time he was prematurely decrepit , and Crown Prince Jean - Baptiste Bernadotte took over the government as soon as he landed in Sweden in 1810 . By the Union of Sweden and Norway on 4 November 1814 Charles became king of Norway under the name Carl II of Norway . After eight years as king only by title , Charles died without a natural heir on 5 February 1818 , and Bernadotte succeeded him as King Charles XIV John . He was the 872nd Knight of the Order of the Golden Fleece in Spain . Family . He married his cousin Hedwig Elizabeth Charlotte of Holstein - Gottorp ( 1759 – 1818 ) , on 7 July 1774 in Stockholm . Both of their children died in infancy : With Augusta von Fersen , he had an extramarital son : Adopted sons : Ancestors . < / div >