Frederick the Great sibling Wilhelmine of Prussia, Margravine of Brandenburg-Bayreuth
Katte affair
Soon after his relationship with Keith ended, Frederick became close friends with Hans Hermann von Katte, a Prussian officer several years older than Frederick who became one of his boon companions and may have been his lover. After the English marriages became impossible, Frederick plotted to flee to England with Katte and other junior army officers. While the royal retinue was near Mannheim in the Electorate of the Palatinate, Robert Keith, who was Peter Keith's brother and also one of Frederick's companions, had an attack of conscience when the conspirators were preparing to escape and begged Frederick William for forgiveness on 5 August 1730. Frederick and Katte were subsequently arrested and imprisoned in Küstrin. Because they were army officers who had tried to flee Prussia for Great Britain, Frederick William levelled an accusation of treason against the pair. The king briefly threatened the crown prince with execution, then considered forcing Frederick to renounce the succession in favour of his brother, Augustus William, although either option would have been difficult to justify to the Imperial Diet of the Holy Roman Empire. The king condemned Katte to death and forced Frederick to watch his beheading at Küstrin on 6 November, leading the crown prince to faint just before the fatal blow.Frederick was granted a royal pardon and released from his cell on 18 November 1730, although he remained stripped of his military rank. Rather than being permitted to return to Berlin, he was forced to remain in Küstrin and began rigorous schooling in statecraft and administration for the War and Estates Departments. Tensions eased slightly when Frederick William visited Küstrin a year later, and Frederick was allowed to visit Berlin on the occasion of his sister Wilhelmine's marriage to Margrave Frederick of Bayreuth on 20 November 1731. The crown prince returned to Berlin after finally being released from his tutelage at Küstrin on 26 February 1732 on condition that he marry Elisabeth Christine of Brunswick-Bevern.
brother or sister kin