Charles XIV and III John or Carl John, (Swedish and Norwegian: Karl Johan; 26 January 1763 – 8 March 1844) 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 was appointed as a Marshal of France by Napoleon, 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. 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. Bernadotte was born in Pau, France, as the son of Jean Henri Bernadotte, prosecutor at Pau, and his wife Jeanne de Saint-Jean. At the age of 14, he was apprenticed to a local attorney. The early death of his father, however, stopped him from following in his father's career. Bernadotte joined the army as a private in the Régiment Royal–La Marine on 3 September 1780, and first served in the newly conquered territory of Corsica. In early 1790 he was promoted to Adjutant-Major. Following the outbreak of the French Revolution, his eminent military qualities brought him speedy promotion. By 1794 he was promoted to brigadier, attached to the Army of Sambre-et-Meuse. After Jourdan's victory at Fleurus (26 June 1794) he then became a divisional general. He declined to help Napoleon Bonaparte stage his coup d'état of November 1799 but nevertheless accepted employment from the Consulate, and from April 1800 to 18 August 1801 commanded the army in the Vendée. On the introduction of the First French Empire, Bernadotte became one of the eighteen Marshals of the Empire, and from June 1804 to September 1805 served as governor of the recently occupied Hanover. In 1810 Bernadotte was about to enter his new post as governor of Rome when he was unexpectedly elected the heir-presumptive to King Charles XIII of Sweden. Bernadotte was elected partly because a large part of the Swedish Army, in view of future complications with Russia, was in favour of electing a soldier, and partly because he was also personally popular, owing to the kindness he had shown to the Swedish prisoners in Lübeck. On 2 November Bernadotte made his solemn entry into Stockholm, and on 5 November he received the homage of the Riksdag of the Estates, and he was adopted by King Charles XIII under the name of "Charles John" (Karl Johan). At the same time, he converted from Roman Catholicism to the Lutheranism of the Swedish court.

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