Most modern scholars agree that Prussian King Frederick the Great (1712–1786) was primarily homosexual.; also see: Wolfgang Burgdorf, Friedrich der Große: Ein biografisches Porträt (Freiburg im Breisgau: Herder, 2011), 76–103, presents the most comprehensive list of Frederick's male lovers.Krysmanski, Bernd (2019), "Belege für die Homosexualität und die analerotischen Gelüste des Preußenkönigs," in Nur Hogarth zeigt den Alten Fritz wahrheitsgemäß mit krummem "Zinken"die uns vertrauten Bilder von Pesne bis Menzel tun dies nicht (Heidelberg: arthistoricum.net). https://archiv.ub.uni-heidelberg.de/artdok/6399 ("Evidence for the Homosexuality and the Anal-Erotic Desires of the Prussian King," in Only Hogarth Depicts the Old Fritz Truthfully with a Crooked "Beak" – The Pictures Familiar to Us from Pesne to Menzel Don't Do This), p. 27: "Dass der Preußenkönig homosexuelle Neigungen hatte, war schon dem 18. Jahrhundert wohlbekannt." ("That the Prussian king had homosexual tendencies was well known as early as the 18th century.") However, the nature of his actual relationships remains a source of speculation. For instance, there is no consensus on the actual number of Frederick's male lovers. Some researchers believe that he may have only lived out his same-sex love platonically. This latter point is contradicted by some statements by the king himself and by his contemporaries, Voltaire and Casanova.

Though he had an arranged marriage, Frederick produced no children and was succeeded by his nephew. His favoured courtiers were exclusively male, and his art collection celebrated homoeroticism. Persistent rumours connecting the king with homosexual activity circulated around Europe during his lifetime, but there is less surviving definitive evidence of any sexual relationships of his, homosexual or otherwise. However, in July 1750, the Prussian king teasingly wrote to his gay secretary and reader, Claude Étienne Darget: ('My hemorrhoids affectionately greet your penis'), which strongly suggests that he was sexually involved with men.Œuvres de Frédéric le Grand, Tome XX, Correspondance Tome V: IV. Correspondance de Frédéric avec M. Darget (Mai 1749 - 6 Septembre 1771), no. 6.Krysmanski, "Evidence for the homosexuality and the anal erotic desires of the Prussian king", p. 28. https://doi.org/10.11588/artdok.00008019

Furthermore, at an advanced age, the king advised his nephew in a written document against passive anal intercourse, which from his own experience was "not very pleasant".In his "Matinées" (a kind of guide written for his heir to the throne) to be found in the royal archives in Potsdam, the older monarch took a more sceptical view of his homosexual activities. Though on the one hand he admits that Amor knows no mercy and that it is useless to defy him, yet, on the other hand, he advises his nephew not to follow his example, because it could have serious consequences for him: "the commanders and officers would be more interested in pleasure than glory, and your army would end up in a collection of pederasts, like your Uncle Henry's regiment. From my personal experience I can assure you that that Greek pleasure has little appeal..." See Gaston Vorberg, "Der Klatsch über das Geschlechtsleben Friedrichs II." (Gossip about Frederick II's sexual life), in Abhandlungen aus dem Gebiete der Sexualforschung (Treatises from the field of sexual research), vol. III, no. 6 (1920-21), pp. 6-7. That he actually did desire men is also clear from statements by his famous contemporaries, Voltaire and Giacomo Casanova, who personally knew him and his sexual preferences. Significantly, Voltaire nicknamed Frederick "Luc". When read backwards, it means (the vulgar French term for 'anus' or 'butt').Oliver Das Gupta, "Der schwule Fritz," Süddeutsche Zeitung, 23 January 2012. According to Wolfgang Burgdorf, "Various foreign envoys... reported on Frederick's 'unnatural vice'.... None of them bothered with the idea of influencing the Prussian court's policy by launching a new mistress. Saxony and France, however, repeatedly managed to place good-looking young men near him. Sanssouci was a women-free zone during the Friderican era."Wolfgang Burgdorf, "Königliche Liebschaften: Friedrich der Große und seine Männer," in Norman Domeier and Christian Mühling (eds.), Homosexualität am Hof: Praktiken und Diskurse vom Mittelalter bis heute (Frankfurt am Main and New York: Campus), p. 133. Frederick himself once shocked a dinner party with an offensive rant against "ghastly women you smelled ten miles around."

Frederick's sexuality was rejected by professional historians for centuries after his death, but was extensively discussed in the first decades of the twentieth century, with LGBT researchers and publications in Weimar Germany celebrating him as a queer predecessor and pioneer.

Possible homosexual relationships

As a young crown prince, Frederick confided to his mentor, Generalfeldmarschall Friedrich Wilhelm von Grumbkow, that he felt too little attracted to the female sex to be able to imagine entering into a marriage.Reinhard Alings, "'Don't Ask, Don't Tell' - war Friedrich schwul?" in Friederisiko: Friedrich der Große: Die Ausstellung, edited by the Generaldirektion der Stiftung Preußische Schlösser und Gärten Berlin-Brandenburg (Munich, 2012), p. 238. At age 16, Frederick seems to have embarked upon a youthful affair with Peter Karl Christoph von Keith, a 17-year-old page of his father. Rumors of the liaison spread in the court, and the "intimacy" between the two boys provoked the comments of Frederick's sister Wilhelmine who wrote, "Though I had noticed that he was on more familiar terms with this page than was proper in his position, I did not know how intimate the friendship was." Rumors finally reached King Frederick William, who cultivated an ideal of ultramasculinity in his court, and derided his son's supposedly effeminate tendencies. As a result, Keith was dismissed from his service to the king and sent away to a regiment by the Dutch border, while Frederick was sent to the king's hunting lodge at Wusterhausen in order to "repent of his sin"."

King Frederick William may have thought that Frederick's relationship with Hans Hermann von Katte, another royal page who had succeeded Keith as Frederick's favorite, was also romantic, a suspicion which may have played a role in Katte's receiving a death sentence. Frederick himself only escaped a death sentence thanks to Emperor Charles VI's intervention., p. 41 A contemporary courtier, Karl Ludwig von Pöllnitz, reports that Katte, eight years his senior, and Frederick treated each other “like a lover with his mistress.”Christopher Clark quotes this remark in his book Preußen. Aufstieg und Niedergang 1600–1947 (″Prussia. Rise and Decline 1600–1947″), publisher DVA, Stuttgart 2006, pages 135 and 800, as "credible". Princess Wilhelmine wrote about Katte: "He played the role of a free spirit and took his life to excess; Great ambition and arrogance went hand in hand with this vice. Such a favorite was far from dissuading my brother from his aberrations".Wilhelmine of Prussia, Margravine of Brandenburg-Bayreuth: Mémoires de Frédérique Sophie Wilhelmine, Margrave de Bayreuthe, soeur de Frédéric le Grand, depuis L’année 1709 jusqu’a 1742, écrit de sa main. (Mercure de France, Paris 1967), translated into German and edited by Günther Berger as: Memoiren einer preußischen Königstochter. Markgräfin Wilhelmine von Bayreuth (Memoirs of a Prussian king's daughter. Margravine Wilhelmine of Bayreuth), publisher Ellwanger, Bayreuth 2007, 3rd edition, 2018, pp. 93−94

While confined to Kustrin after the Katte affair, Frederick formed an intimate friendship with Michael Gabriel Fredersdorf, with whom Frederick romantically corresponded and for whom he demonstrated frequent concern. Fredersdorf initially became Frederick's valet, and when Frederick became king he was provided with an estate and acted as factotum and, as some have said, as an unofficial prime minister. In 1789, Frederick's garden inspector and Oberhofbaurat [head of the planning department and building control office] Heinrich Ludewig Manger described Fredersdorf as "the king's darling at the time".Heinrich Ludewig Manger's Baugeschichte von Potsdam, besonders unter der Regierung König Friedrichs des Zweiten, vol. 1 (Berlin and Stettin: Nicolai, 1789–90), p. 34. Reporting the dismissal of Friedrich Wilhelm Diterich, the building inspector of Sanssouci, Manger suspects that Diterich "did not court the king's darling at the time (i.e. Fredersdorf) enough". Historian Eva Ziebura says: "The two of them probably had sex at the beginning".War Friedrich schwul oder nur not-homosexuell?, Die Welt, 23 January 2012. Eva Ziebura is a biographer of his brother Prince Henry: Eva Ziebura: Prinz Heinrich von Preußen. Biographie (in German), publisher; Aufbau-Taschenbuch-Verlag, Berlin, 496 pages, 2004, Later they exchanged very intimate letters about their issues with constipation, potency issues, etc.Oliver Das Gupta: Der schwule Fritz, in Süddeutsche Zeitung, 23 January 2012 Another intimate confidante was his equerry: "No lover can be more agreeable and obliging than Frederick with Dietrich von Keyserling", said a councillor of war. He was nicknamed “Caesarion” and was promoted from equerry to adjutant general. Another favorite was Lieutenant General Friedrich Rudolf von Rothenburg, who took part in the Round Table until his death in 1751 and regularly stayed in one of Sanssouci's guest rooms, which is still called the Rothenburg Room today. The king liked to take good-looking soldiers into his personal service. Numerous young pages also served at his court.

In 1746, Frederick wrote mocking letters to his rather openly gay brother, Prince Henry of Prussia, which were characterized by jealousy for the "handsome Marwitz",Eva Ziebura, Prinz Heinrich von Preußen (Berlin: Stapp, 1999), pp. 44–48. The "handsome Marwitz" is presumably identical to the member of the von der Marwitz family mentioned on the Rheinsberg obelisk (without mentioning his first name) as "quartermaster in the king's army" with the life span 1724–1759. a young royal page. One of Henry's favorites, the Queen's chamberlain, Ernst Ahasverus Heinrich von Lehndorff, also recalls this story in his memoirs.Wieland Giebel (editor): Die Tagebücher des Grafen Lehndorff. Die geheimen Aufzeichnungen des Kammerherrn der Königin Elisabeth Christine (The diaries of Count Lehndorff. The Secret Notes of Queen Elisabeth Christine's Chamberlain), publisher: Story, Berlin 2007, . The king wrote to his brother on March 3, 1746, from Potsdam: "Your little darling is doing very well and if he stays well behaved, you will see him again soon. At the moment he yearns for love and composes elegies in your honor full of hot kisses, which he intends to give you on your return. I advise you to conserve your strength so that you have enough to assert your love."The letter of March 3, 1746 is cited by Eva Ziebura: Prinz Heinrich von Preußen. Biographie, p. 44 He also warned his brother about certain young men at court or among the officers he believed to suffer from gonorrhea.

Voltaire