Charles XIV & III John, also known as Carl John, (Swedish and Norwegian: Karl Johan) was King of Sweden (as Charles XIV John) and King of Norway (as Charles III John) from 1818 until his death and served as de facto regent and head of state from 1810 to 1818. He was also the Sovereign Prince of Pontecorvo, in south-central Italy, from 1806 until 1810.
He was born Jean Bernadotte in France and served a long career in the French Army. He subsequently acquired the full name of Jean-Baptiste Jules Bernadotte. He was appointed as a Marshal of France by Napoleon I, though the two had a turbulent relationship. Napoleon made him Prince of Pontecorvo on 5 June 1806, but he stopped using that title in 1810 when his service to France ended and he was elected the heir-presumptive to the childless King Charles XIII of Sweden. His candidacy was advocated by Baron Carl Otto Mörner, a Swedish courtier and obscure member of the Riksdag of the Estates. Upon his Swedish adoption, he assumed the name Carl. He did not use the name "Bernadotte" in Sweden, but founded the royal dynasty there of that name.