Count Hans Axel von Fersen (September 4, 1755 - June 20, 1810) was a Swedish army officer, diplomat and statesman.

He was the son of the statesman Fredrik Axel von Fersen and grandson of General Hans Reinhold Fersen. He was carefully educated at home, at the Carolinum at Brunswick in Turin, and in Strasbourg. In 1779 he entered the French military service with the Royal-Bavière regiment, accompanied General Rochambeau to America as his adjutant, served as interpreter between him and General Washington, distinguished himself during the war with the Kingdom of Great Britain, notably at the siege of Yorktown, 1781, and in 1785 was made proprietory colonel of the regiment Royal Suédois. He is famous as a lover and had affairs with various women, especially the Italian-born adventuress Eleanore Sullivan, and evidently the Royal Duchess Hedwig Elizabeth Charlotte of Holstein-Gottorp, married to the future King Charles XIII of Sweden.

The young nobleman was, from the first, a prime favourite at the French court, owing partly to the recollection of his father's devotion to France, but principally because of his own amiable and brilliant qualities. Queen Marie Antoinette, who had first met Fersen when they both were age 18, was especially attracted by the grace and wit of "le beau" Fersen, who had inherited his full share of the striking handsomeness which was hereditary in the family. It is possible that Fersen would have remained at Versailles, following the American war, but he was commanded by his own sovereign, then at Pisa, that he desired him to join his suite. Fersen accompanied Gustav III of Sweden in his tour of Italy and France, and returned home with him in 1784.

In 1785 Marie Antoinette would give birth to Louis-Charles, the first titular Duke of Normandy in centuries. Afterwards Louis XVI wrote in his journal that it had happened just as when "his own son" had been born. Some have claimed that Louis-Charles, later Dauphin of France, was the biological child of Marie Antoinette and Fersen. However, this is extremely unlikely. Some have claimed that Louis XVI actually meant when "his first son" was born. Secondly, little Louis XVII was noted to resemble two members of the Bourbon family: his paternal uncle Charles X (Louis XVI's youngest brother) and his late grandmother, Princess Maria-Josefa (Louis XVI's mother). The claim that Fersen was the biological father of Louis XVII has been discounted by the child's recent biographer, Deborah Cadbury, and by Marie-Antoinette's biographer Antonia Fraser. This question is answerable today through DNA analysis but no one as yet has undertaken to do this as they did with the Russian Imperial Family.

When Gustav III's war with Russia broke out, in 1788, Fersen accompanied his monarch as an adjutant to Finland, but in the autumn of the same year was sent to France, where the political horizon was already darkening. It was necessary for Gustav III to have an agent thoroughly in the confidence of the French royal family, and, at the same time, sufficiently able and audacious to help them in their desperate straits, especially as he had lost all confidence in his accredited minister, the Baron Erik Magnus Staël von Holstein. With his usual acumen, he fixed upon Fersen, who was at his post early in 1790. Before the end of the year he was forced to admit that the cause of the French monarchy was hopeless so long as the king and queen of France were nothing but captives in their own capital, at the mercy of an irresponsible mob.

He had the leading role in the royal family's flight to Varennes. He found most of the requisite funds at the last moment. He ordered the construction of the famous carriage for six, in the name of the baroness von Korff, and kept it at his own home on the Rue Matignon, so that all Paris might get accustomed to the sight of it. He was the coachman of the fiacre which drove the royal family from the Carrousel to the Porte Saint-Martin, where the carriage awaited them. He accompanied them as far as Bondy, the first stage of their journey.

In August 1791, Fersen was sent to Vienna to induce the emperor Leopold to accede to a new coalition against revolutionary France, but he soon came to the conclusion that the Austrian court meant to do nothing at all. At his own request, therefore, he was transferred to Brussels, where he could be of more service to the queen of France. In February 1792, at his own mortal peril, he once more succeeded in reaching Paris in disguise and with counterfeit credentials as minister plenipotentiary to Portugal. On the 13th he arrived, and the same evening contrived to steal an interview with the queen in the Tuilleries Palace itself, unobserved. On the following day he was with the royal family from six o'clock in the evening till six o'clock the next morning, and convinced himself that a second flight was physically impossible. On the afternoon of the 21st he succeeded in paying a third visit to the Tuileries, stayed there till midnight and succeeded, with great difficulty, in reaching Brussels on the 27th. This perilous expedition, a monumental instance of courage and loyalty, had no substantial result. There followed some years of relative inactivity after Gustav III's assassination in 1792 and the execution of the French king and queen in 1793. In 1797 Fersen was sent to the Second Congress of Rastatt as the Swedish delegate, but in consequence of a protest from the French government, was not permitted to take part in it.

During this congress it is told that Napoléon simply called him Monsieur, neglecting the fact that he was an appointed ambassador, a count, and one of the Lords of the Realm of Sweden (en av Rikets Herrar). Napoléon declared that he would never discuss anything with a person who had had an affair with the widow Capet (Marie Antoinette). Fersen thereupon served the following two years as Sweden's envoy to the court of Baden.

During the regency of the Duke Charles of Södermanland (1792-1796) Fersen, like other prominent Gustavians, or loyal supporters of the late Gustav III, was in disgrace; but, when Gustav IV Adolf attained his majority in 1796, Fersen was welcomed back to court with open arms. In 1799 he was made chancellor of Uppsala University to suppress radical student unrest and in 1801 was appointed Riksmarskalk, or Marshal of the Realm. On the outbreak of the war of the Third Coalition with Napoleon in 1805, Fersen accompanied Gustav IV Adolf to Germany as his political advisor. He prevented Gustav Adolf from attacking Prussia when it declined to join the war against France. During the rest of Gustav IV Adolf's reign Fersen was therefore in semi-disgrace, though he continued to serve in Sweden's interim governments when the king was abroad.

Fersen stood aloof from the revolution of 1809 that deposed Gustav IV Adolf. His sympathies lay with Prince Gustav of Vasa, son of the deposed monarch, and he was believed to desire the prince's legitimate succession to the throne. The Riksdag, or parliament, however elected as successor the highly popular Danish prince Carl August of Augustenburg. When the new crown prince suddenly died in Skåne in May 1810, the rumor spread that he had been poisoned, and that Fersen and his sister, the countess Sophie Piper, were accessories. The source of these accusations has never been discovered. But it was eagerly taken up by the anti-Gustavian press, and popular suspicion was especially aroused by a fable called 'The Foxes' directed against the Fersens, which appeared in the radical newspaper Nya Posten.

When on June 20, 1810, the prince's body was conveyed to Stockholm, Fersen, as Marshal of the Realm, received it at the barrier and led the funeral cortege into the city. His fine carriage and splendid dress seemed to spectators an open derision of the general grief. The crowd began to murmur and presently to throw stones and cry "murderer!" He was forced to seek refuge in a house near the Riddarhus Square, but the mob rushed after him, brutally maltreated him, tearing his clothes to pieces. At this time the Royal Life Guards standing in formation on the square, attempted to protect Fersen, but the commanding officer gave the order "För fot gevär!" (English: Attention! Rifles by the foot).

To quiet the people and save the unhappy victim, two officers volunteered to conduct him to the court house and there place him in arrest. But he had no sooner been taken there than the crowd, which had followed him all the way beating him with sticks and umbrellas, broke in, dragged him out, and kicked and trampled him to death. The riot, which lasted more than an hour, happened, too, in the presence of numerous troops, who were forbidden to rescue the Marshal of the Realm from his tormentors. Later that evening the troops fired on the rioters, killing and wounding several of them.

In the circumstances, one must adopt the opinion of Fersen's contemporary, Baron Gustaf Armfelt, "One is almost tempted to say that the government wanted to give the people a victim to play with, just as when one throws something to an irritated wild beast to distract its attention. The more I consider it all, the more I am certain that the mob had the least to do with it. . . . But in God's name what were the troops about? How could such a thing happen in broad daylight during a procession, when troops and a military escort were actually present?"

The responsibility must ultimately rest with the government of Charles XIII of Sweden, which apparently intended to intimidate the Gustavians by a riot directed against one of their most conspicuous figures. The King is reported to have said the day before, "Det skadar inte om den förnäma herren får lite smuts i sin vagn." (English: "It won't hurt if that distinguished gentleman gets some dirt in his carriage"). Armfelt was absent at the time, so Fersen fell victim.

Axel von Fersen died that day in Stockholm as formally Sweden’s highest ranking official next to the King. His death sent shockwaves throughout the country. The cause of death was determined to be "crushing of the ribcage" when the sailor Otto Johan Tandefelt jumped with both feet on Fersen's chest.

A few months after the murder Axel von Fersen and his family were cleared of any suspicion connected with the death of Carl August of Augustenburg, and he finally received a state burial with all pomp and ceremony. His sister Sofie Piper thereafter withdrew from Stockholm to her Löfstad manor, near Norrköping. Here she raised a memorial to her brother, with the inscription:

Åt en oförgätlig broder, mannamodet uti hans sista stunder den 20 juni 1810 vittna om hans dygder och sinnes lugn (English: "To an unforgettable brother, the courage in his last moments on the 20th of June 1810, bears testimony to his virtues and clean conscience")

Count Hans Axel von Fersen: Aristocrat in an Age of Revolution by H. A. Barton ISBN 0-8057-5363-X * The Fatal Friendship by Stanley Loomis ISBN 0-931933-33-1