Charles XIV John (Karl XIV Johan), born Jean-Baptiste Bernadotte, later renamed Jean-Baptiste Jules Bernadotte (26 January 1763 – 8 March 1844) was King of Sweden and the King of Norway (where he was known in Norwegian as Karl III Johan) from 1818 until his death. He was also the first Sovereign Prince of Pontecorvo, Italy.
French by birth, Bernadotte served a long career in the French Army. He was appointed as a Marshal of France by Napoleon I, though the two had a turbulent relationship. His service to France ended in 1810, when he was elected the heir to the Swedish throne - because the Swedish royal family was dying out with King Charles XIII, with both of his children having died in infancy.
He had a brother named Jean Bernadotte (Pau, Béarn, 1754 – Pau, Béarn, 8 August 1813) who was made 1st Baron Bernadotte and married Marie Anne Charlotte de Saint-Paul. Their paternal grandparents were Jean Bernadotte (Pau, 29 September 1683 – Pau, 3 October 1760) and wife (married at Pau, 1 May 1707) Marie du Pucheu dite de La Place (Pau, 6 February 1686 – Pau, 5 October 1773), daughter of Jacques du Pucheu de La Place and wife Françoise de Labasseur. Their maternal grandparents were Jean de Saint-Vincent (Boëil-Bezing, c. 1690 – Boëil-Bezing, 21 May 1762) and wife (married at Assat, 30 May 1719) Marie d'Abbadie de Sireix (Sireix, 25 March 1694 – Boëil-Bezing, 16 October 1752), daughter of Doumengé Habas d'Arrens and wife Marie d'Abbadie, Lay Abbess of Sireix. Finally, they were the great-grandsons of Jean Bernadotte (Pau, 7 November 1649 – Pau, 14 July 1689) and wife (married at Pau, 18 June 1674) Marie de la Barrère-Bertandot; he was the son of Pierre Bernadotte and wife Margalide Barraquer and paternal grandson of Joandou du Poey, born in 1590, and wife Germaine de Bernadotte.
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). The new Crown Prince was very soon the most popular and most powerful man in Sweden. The infirmity of the old King and the dissensions in the Privy Council of Sweden placed the government, and especially the control of foreign affairs, entirely in his hands. The keynote of his whole policy was the acquisition of Norway and Bernadotte proved anything but a puppet of France. In 1813, he allied Sweden with Napoleon's enemies, Great Britain and Prussia, of the Sixth Coalition, in order to secure this. After the defeats at Lützen (2 May 1813) and Bautzen (21 May 1813), it was the Swedish Crown Prince who put fresh fighting spirit into the Allies; and at the conference of Trachenberg he drew up the general plan for the campaign which began after the expiration of the Truce of Plaswitz. Charles John, as the Commander-in-Chief of the Northern Army, successfully defended the approaches to Berlin against Oudinot in August and against Ney in September at the Battles of Grossbeeren and Dennewitz; but after the Battle of Leipzig he went his own way, determined at all hazards to cripple Denmark and to secure Norway.
As the union King, Charles XIV John, who succeeded to that title in 1818 following the death of Charles XIII, was initially popular in both countries. Upon his accession he converted from Roman Catholicism to the Lutheranism of the Swedish court. He would never learn to speak Swedish or Norwegian, though this did not pose a serious obstacle to his rule, since French was widely spoken by all of the aristocracy of the time.
Charles XIV John's reign witnessed the completion of the southern Göta Canal, begun 22 years earlier, to link Lake Vänern to the sea at Söderköping 180 miles to the east. Though his ultra-conservative views were unpopular, particularly from 1823 onwards, his dynasty never faced serious danger. Swedes and Norwegians alike were proud of a monarch with a good European reputation. Though the Riksdag of the Estates of 1840 meditated compelling him to supposedly abdicate, he survived that controversy, and his silver jubilee was celebrated with great enthusiasm in 1843.
Charles XIV John died at Stockholm on 8 March 1844. His reign was one of uninterrupted peace, during which his kingdoms experienced great material development. He was succeeded by his son, Oscar I of Sweden and Norway. Oscar's mother was Désirée Clary, Napoleon Bonaparte's first fiancée. Her sister, Julie Clary, was married to Napoleon's brother, Joseph Bonaparte. Désirée chose Napoleon to be prince Oscar's godfather.
The main street of Oslo, Karl Johans gate is named for him, while the Fortress of Karlsborg (Karlsborgs fästning) located in Karlsborg Municipality (Karlsborgs kommun) in Västra Götaland, was named by him after Charles XIII, his adoptive father.
During the French Revolution, Bernadotte belonged for a time to the Jacobin Club, a radical political organization. According to a popular myth, after his death a tattoo was supposedly found on his body that read Mort aux rois! ("Death to kings!"), presumably a legacy of his Jacobin days. However, no evidence has been found to confirm this.