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 this capacity, as well as during his later command of the army of northern Germany, he built a reputation for independence, incorruptibility, moderation, and administrative ability. Bernadotte's rule was popular, and despite the exactions taken from the populace as part of Napoleon's policy of making occupations pay for themselves, Hanover's economy prospered. Bernadotte extended his protection and made private contributions to
Gottingen University, befriending many of the professors and other men of learning whom he often had over for dinner and employed to tutor himself and his wife. During the campaign of 1805, Bernadotte, with his army corps from Hanover, formed into the I Corps, commanded the Left Wing of the
Grande Armée overseeing
Auguste de Marmont's II Corps and having the majority of the
Bavarian Army attached to his command; some 65,000 men or 1/4th of the Army. Bernadotte was also tasked with assuring France's newest ally, the Elector of Bavaria,
Maximillian IV Joseph, that the Austrians would be driven from his country. Bernadotte, with
Davout's III Corps attached to his command, and the Bavarians, gained a victory over the Austrians, driving them out of
Munich on 12 October, taking some 3000 prisoners and 19 guns and installing Maximillian Joseph back onto his throne. I Corps then co-operated in the
great movement which resulted in the shutting off of
Mack in the
Battle of Ulm. Bernadotte's troops then captured
Salzburg on 30 October. In the
Battle of Austerlitz (2 December 1805) he was posted with his corps in the center between
Soult and
Lannes, and contributed to defeating the attempt of the right wing of the allies to outflank the French army. As a reward for his services at Austerlitz, he became the 1st Sovereign
Prince of Pontecorvo (5 June 1806), a district in southern Italy formerly subject to the Pope. During the 1806 campaign against
Prussia, Bernadotte was reproached by Napoleon for not participating with his army corps in the battles of
Jena and
Auerstädt (14 October 1806). Napoleon, on the night of 13 October, thinking he had faced the whole
Prussian Army at Jena, sent orders to Davout, through Marshal Berthier, Davout relayed the order to Bernadotte at 0400 on 14 October with the order stating: "If the Prince of Ponte Corvo [Bernadotte] is with you, you may both march together, but the Emperor hopes that
he will be in the position which had been indicated at Dornburg." This was in accordance with Bernadotte's last set of written orders from 12 October, which ordered him and Davout to get across the Prussian line of retreat. In pursuance of these orders, Bernadotte, separately from Davout, left
Naumburg at dawn on the morning of the 14th for Dornburg and marched toward
Apolda, which he reached by 16:00. Hampered by the very poor state of the roads, and a steep defile within which Dornburg is situated and the narrow bridge which passes over the
Saale, that could pass but one artillery piece at a time according to General
Dupont, he could not engage in the Battle of Jena, though he effectively compelled the Prussians to retreat from both battlefields by posting his troops on the heights of Apolda. The defile was such an obstacle that Bernadotte's 3rd Infantry division, commanded by
Jean-Baptiste Drouet, Comte d'Erlon, was still in the midst of crossing the bridge well after nightfall, making it unlikely that Bernadotte could have intervened at Auerstädt in any event. He later was accused of deliberately refusing to support Davout, who had unexpectedly encountered the Prussian main army at Auerstädt, out of jealousy, and Napoleon, if reminiscences from
St. Helena may be believed, once intended to put Bernadotte before a court-martial. In fact, he did what he had been ordered to do, and more fundamental responsibility for his absence rests upon the ambiguous and indirect orders issued by Berthier and Napoleon's unawareness of the Prussian position. Documentary evidence supports Bernadotte's assertion that he was ordered to Dornberg, as no orders from Napoleon to Bernadotte to march with Davout were ever found in French Imperial Archives, while Berthier's order of 14 October was confirmed. After the Battle of Jena, Bernadotte crushed the Prussian Reserve Army, all fresh troops fortified behind a marsh and the River Saale, under Duke
Eugen of Württemberg at
Halle (17 October 1806), though Imperial Headquarters did not much appreciate this victory. When visiting Halle after the battle, and commenting on the degree of difficulty of storming a fortified position accessible only by a single bridge, Napoleon enigmatically commented, "Bernadotte stops at nothing. Someday the Gascon will get caught." Subsequently, Bernadotte pursued, conjointly with Soult and
Murat (known as the "Pursuit of the Three Marshals"), Prussian general
Blücher's Corps to
Lübeck, where his troops stormed the Prussian defenses, taking the city and forcing Blücher's capitulation at
Ratekau (7 November 1806). When the French forced their way into
Lübeck, the city became the target of large-scale looting and rampage by the French soldiers. Bernadotte, struggling desperately to prevent his men from sacking the city, was given six horses from the Council of Lübeck as a token of their appreciation. He also treated with courtesy 1600 Swedish prisoners, under the command of Colonel Count Gustaf Mörner, and allowed them to return to their home country. The impressed Swedes went home with a tale of Bernadotte's fairness in maintaining order within the city. Count Mörner would later play a prominent role in the election of Bernadotte as Crown Prince of Sweden. Thereafter, he marched to Poland in command of the French Left Wing, composed of his I Corps and
Ney's VI Corps. Left unsupported by Ney's unexpected movement toward
Königsberg, the Russians under
Levin August von Bennigsen passed over to the offensive and attempted to destroy Bernadotte's and Ney's isolated Corps. Napoleon, having received word of the Russian offensive, gave word to Bernadotte to retreat West to draw the Russians toward him so that Napoleon could then cut off and surround the Russians. Bernadotte moved West as ordered, pursued by Bennigsen, where he defeated the numerically superior Russian vanguard at
Mohrungen (25 January 1807). During the battle, Bernadotte's personal wagon was captured by the Russians, and he was accused, by the
Cossacks who looted his baggage, of having extorted a large quantity of silver plate from minor German states. This claim is unsubstantiated and contrary to his reputation. He was known throughout the army for his probity and honesty in the conduct of his affairs on campaign, and he refrained from the looting and brigandage that many of his fellow marshals engaged in. As a consequence, his table fare was considered poor by his brother marshals, and while others dined on fine service and employed chefs, he habitually used his own money to pay for food for his troops, and to give money awards to those who merited recognition. He held his troops to the same high standard; he punished looting and rape severely, and was known to intervene with his sword drawn against those engaged in pillaging, as was the case following the capture of Lübeck. Due to the capture of a courier carrying the Emperor's latest orders, Bernadotte was not informed of a change of strategy to move East toward the rest of the French Army. As a consequence, Bernadotte's I Corps was too far away to take part in the
Battle of Eylau (7 to 8 February 1807). Napoleon rebuked him for his absence, but it became acknowledged that it was not due to Bernadotte but Berthier's carelessness in dispatching the orderly. The Russians resumed the offensive that summer and Bernadotte was attacked by, and defeated, a strong Prussian Corps at
Spanden, preserving the French bridgehead over the
Pasłęka, where he was nearly killed when a spent ball struck him in the neck. Due to this near-fatal wound, Bernadotte was invalided to the rear and missed the remainder of the Polish Campaign. After the
Peace of Tilsit, on 14 July 1807, he became governor of the
Hanseatic towns, where he once again proved his administrative and diplomatic abilities and was well-liked. He was to direct the expedition against Sweden, via the Danish islands, but the plan came to naught because of the want of transports and the defection of the
Spanish contingent, which went back to Spain to fight against Napoleon at the start of the
Peninsular War. Pursuant to the projected invasion of Sweden, and by virtue of Denmark becoming an ally of France in 1808, Bernadotte found himself de facto head of a French occupation of Denmark. He maintained strict discipline of his troops, and his good treatment of the Danes made him popular with the populace and the Danish Royal Family. Upon his departure from Denmark, he was one of the few Frenchmen of the period to be awarded the
Order of the Elephant. During Bernadotte's time as governor of the Hanseatic cities, the
Abdications of Bayonne occurred, an event that triggered the Peninsular War, which would play such a large role in Napoleon's defeat. For a time, Napoleon considered the notion of placing Bernadotte on the Spanish throne, going so far as to hint at it in a letter to him. Bernadotte informed Napoleon that he did not want the Spanish Crown. Joseph Bonaparte, Bernadotte's friend and brother-in-law, was chosen instead. It was not the first or last time Napoleon considered placing Bernadotte on a foreign throne. Indeed, Napoleon, on several occasions, both during his days as First Consul and as Emperor, considered naming Bernadotte (Napoleon also considered Murat) as his successor by adoption. Despite their rivalry, Napoleon thought Bernadotte alone had the popularity, administrative, and military skill to safeguard the Empire he had built. The birth of the
King of Rome put an end to Napoleon's need for an heir. Ironically, Bernadotte eventually wore a crown, not through the auspices of Napoleon, but as an enemy of France. Recalled to Germany to assist in the
new war between France and Austria, he received the command of the 9th Corps, which was mainly composed of
Saxons. Further difficulties with Berthier, and a saddling with ill-prepared Saxons, combined with an illness, compelled Bernadotte to beg for release from service. Bernadotte wrote to Napoleon that "I see my efforts perpetually paralyzed by a hidden force over which I can not prevail." Napoleon disregarded these appeals, and Bernadotte proceeded with the campaign, commanding mostly foreign troops with few French troops under his command. At the
Battle of Wagram (5 July 1809), he entered battle with his Saxon corps, to which the division of
Dupas was attached and which formed his reserve. Resting on the French Left, Bernadotte's corps was battered during the night but resisted the full fury of the Austrian attack, facing superior numbers. At a critical moment, the officer ordered Dupas forward to his support; the latter replied that he had orders from the emperor to remain where he was. Having been badly mauled and fully exposed ahead of the main French line, IX Corps withdrew from the village of
Aderklaa against Napoleon's orders. On the second day of battle, 6 July 1809, IX Corps, having been mauled the night before, wherein Bernadotte struggled to rally his demoralized Saxons, was attacked by two Austrian corps, as part of
Archduke Charles's effort to break the French line. This time Bernadotte's depleted forceshe had only 6,000 infantry leftbroke and fled (Bernadotte's Corps was not the only one to break that day;
Masséna's troops were also routed by the attack). The routed Saxons retreated in disorder toward
Raasdorf as Bernadotte attempted to rally his men, where he encountered Napoleon. IX Corps rallied and continued to play a role in the battle. Rumors that Napoleon relieved Bernadotte of command on the spot at Raasdorf have long been the stuff of legend, but are not verified. After the battle, Bernadotte complained to Napoleon for having, in violation of all military rules, ordered Dupas to act independently of his command, and for having thereby caused great loss of life to the Saxons, and tendered his resignation. Napoleon accepted after he became aware of an order of the day issued by Bernadotte, which gave the Saxons credit for their courage in terms inconsistent with the emperor's official bulletin. Accounts of Bernadotte's role at Wagram are contradictory. While it is true that IX Corps broke on 6 July, as did other French formations, they later rallied and played a part in the victory. Moreover, Bernadotte fought with exceptional personal courage, at the head of his troops, and narrowly avoided death when attacked by Austrian cavalry. It is likely that IX Corps' poor performance would have been forgotten, and Bernadotte would have retained his command had he never published the controversial Order of the Day. His praise for the Saxons, as well as his mild and courteous treatment of them while under his command, was never forgotten by the Saxon officers and this would later have disastrous consequences for the French when a whole Saxon division defected to Bernadotte's Army of the North during a key moment of the
Battle of Leipzig. With Bernadotte having returned to Paris, the
Walcheren Campaign (July 1809) caused the French ministry, in the absence of the emperor, to entrust him with the defense of
Antwerp with both regular French and Dutch troops, along with the
National Guard. Bernadotte took command of a chaotic situation in which troops from all over the Empire and its vassal states, as well as raw conscripts, were sent to
Holland under divided command. He reorganized and trained his forces, named by the Emperor the Army of Antwerp, by instilling discipline in old soldiers who had been too long at the depots and by teaching raw conscripts their trade. Everywhere he instilled a fighting spirit, making an army out of a mob, and thus he rapidly brought the defenses of Antwerp to a high order of readiness. With Antwerp bristling with cannon and numerous defenders, and with the Army of Antwerp whipped into fighting shape, the British, vexed by poor leadership and with half the army immobilized with fever thanks to the insalubrious islands upon which they were quartered, realized that it was no longer possible to close the
Scheldt, or take Antwerp, and they withdrew their forces. In a proclamation issued to his troops at Antwerp, he made an implied charge against Napoleon of having neglected to prepare the proper means of defense for the Belgian coast. A displeased Napoleon relieved Bernadotte of command of his ad hoc army and ordered his return to Paris, then to
Catalonia to take command of the Army there. Refusing to comply with the order, he was summoned to Vienna, and after an interview with Napoleon at
Schönbrunn, accepted the general government of the Roman departments. ==Offer of the Swedish throne==