Charles XIII or Carl XIII (Swedish: Karl XIII; 7 October 1748 – 5 February 1818) was King of Sweden from 1809 and King of Norway from 1814 to his death. He was the second son (and younger brother to King Gustav III) of King Adolf Frederick of Sweden and Louisa Ulrika of Prussia, sister of Frederick the Great. 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. In Norway, he is known as Charles II. Early life.
https://en.wikipedia.org/wiki/Charles_XIII