Prince Francis Frederick Sigismund of Prussia (German: Franz Friedrich Sigismund; 15 September 1864 – 18 June 1866) was the fourth child and third son of Crown Prince Frederick William of Prussia (later King of Prussia and German Emperor as Frederick III), and Victoria, Princess Royal, eldest daughter of the British Queen Victoria.
Issue. Frederick William II of Prussia (1744–1797) . married (1) Elisabeth Christine of Brunswick-Lüneburg.They had one child Princess Frederica Charlotte of Prussia (1767–1820), who married Prince Frederick, Duke of York and Albany, the second son of George III of the United Kingdom.
Frederick William III of Prussia: 4. William I, German Emperor: 9. Duchess Louise of Mecklenburg-Strelitz: 2. Frederick III, German Emperor: 10. Charles Frederick, Grand Duke of Saxe-Weimar-Eisenach: 5. Princess Augusta of Saxe-Weimar-Eisenach: 11. Grand Duchess Maria Pavlovna of Russia: 1. Prince Waldemar of Prussia: 12. Ernest I, Duke of Saxe ...
Prince Frederick George William Christopher of Prussia (German: Friedrich Georg Wilhelm Christoph Prinz von Preußen; 19 December 1911 – 20 April 1966), also known as Friedrich von Preussen in the United Kingdom, was the fourth son of Crown Prince Wilhelm of Germany and Duchess Cecilie of Mecklenburg-Schwerin
Frederick was the son of Crown Prince Frederick William of Prussia and his wife, Sophia Dorothea of Hanover. He was born sometime between 11 and 12 p.m. on 24 January 1712 in the Berlin Palace and was baptised with the single name Friedrich by Benjamin Ursinus von Bär on 31 January.
Upon Wilhelm's death at the age of ninety on 9 March 1888, the thrones passed to Frederick, who had been German Crown Prince for seventeen years and Crown Prince of Prussia for twenty-seven years. Frederick was suffering from cancer of the larynx when he died, aged fifty-six, following unsuccessful medical treatments for his condition.
Frederick William became King of Prussia on the death of his father in 1840. Through a personal union, he also became the sovereign prince of the Principality of Neuchâtel (1840–1857), today part of Switzerland.