war and conquered its northern portions in 1713, including the ancestral ducal seat Gottorp castle near Schleswig city in the homonymous duchy. In 1721 Frederick IV of Denmark-Norway, being the liege lord in Danish Schleswig who had enfeoffed Charles Frederick with the ducal title in Schleswig in 1702, officially withdrew this fief. Swedish career Charles Frederick met his uncle Charles XII for the first time in 1716. He was declared of legal majority in 1717, and was then given some military responsibility. Charles Frederick was in a tense relationship to his aunt Ulrika Eleonora, whose followers pointed him out to be too rude and arrogant and in lack of any sense of responsibility to be a suitable heir to the throne. Upon the death in 1718 of his maternal uncle and second cousin, Charles XII of Sweden, Duke Charles Frederick was presented as claimant to the throne. However, his aunt Ulrika Eleonora the Younger (1688–1741) managed to wrest the throne for herself, claiming that her elder sister had not "acquired the consent of the Parliamentary Estates" for her marriage to his father, according to laws of succession laid down in Norrköpings arvförening. The duke's party asserted that the absolute monarchy in Sweden, which his grandfather King Charles XI had created, made that marriage clause irrelevant. Upon the news of the death of his uncle, he was reportedly too grief-stricken to take any action. Ulrika Eleonora's husband Frederick I, however, who was also present with him in Tistedalen, rushed to assist her in claiming the throne. When Charles Frederick was confronted with Ulrika Eleonora, he was forced by Arvid Horn to greet her as queen. He asked to be granted the title Royal Highness and to be recognised as her heir, but when her husband instead was given the title, he left Sweden in 1719. In 1723, he was granted the title Royal Highness in his absence, but his pro-Russian policy made him impossible as heir to the Swedish throne. Charles Frederick withdrew from Sweden, eventually settling in Russia, where in May 1725 he married Grand Duchess Anna Petrovna, elder daughter of Tsar Peter the Great. Meanwhile, the so-called Holstein Party in Sweden continued to advance Charles Frederick's claims. The party made preparations and awaited the childless Ulrika Eleonora's death, but Charles Frederick died before his aunt and left his claims to his infant son. By this time however, Sweden had