Prince Frederick Adolf, Duke of Östergötland (; 18 July 1750 – 12 December 1803) was a Swedish Prince, youngest son of King Adolf Frederick of Sweden and Louisa Ulrika of Prussia, a sister of Frederick the Great, King of Prussia. He was given the title Duke of Östergötland. Life During his childhood, Frederick Adolf was under the tutelage of Ulrica Schönström. The Duke was described as "the most beautiful Prince in Europe" and was described as sensitive and spoiled by his mother. He and his sister, Sophia Albertina, were their mother's favourites and also devoted to each other. During family conflicts, such as the famous succession scandal regarding the questioned legitimacy of the Crown Prince in 1778, he and his sister were on their mother's side against that of their brothers Charles and Gustav. As a child, he had a weak health and a fierce temperament. His education became somewhat lacking. Frederik was made colonel in 1762, general major in 1768, general lieutenant in 1774, commander of the Västmanland regiment in 1775 and field marshal in 1792. He was given a minor role in the Revolution of 1772 of his brother Gustav III, who gave him the task of agitating in Södermanland and Östergötland. Reign of Gustav III He was given the title Duke of Östergötland on 8 September 1772 and the Tullgarn Palace as his residence. During the great succession scandal, the so-called Munck Affair in 1778, when the queen dowager Louisa Ulrika questioned the legitimacy of the Crown prince in reference to the rumors that Gustav III had convinced Adolf Fredrik Munck to impregnate the queen, Sophia Magdalena of Denmark, Frederick sided with his mother and defended her before the king by pointing out that these rumors had not been invented by their mother but were in fact widespread rumors, and he reportedly said to his brother the king: "The entire city is talking of it, and it is commonly believed that You are not altogether man, and that it is because of this reason, that You have enticed the Queen to it to have an heir to the Kingdom." It was Frederick who convinced Louisa Ulrika to receive Gustav III on her deathbed in 1782, thereby accomplishing peace between them. His sister-in-law, Hedwig Elizabeth Charlotte of Holstein-Gottorp, describes him as beautiful, with expressive eyes, an easygoing temper, and very handsome when he dresses properly, though often badly