Like some other Hohenzollerns like Prince Heinrich of Prussia, Friedrich was greatly interested in aviation.[1] In 1911, he began building an aeroplane at Glenicke Castle, with the hopes of trying it out the following spring.[1] In 1917, he and his brother Friedrich Karl joined the German flying corps.[2] Later that year, his brother died from war wounds.
Louise Victoria Margaret Antoinette Sieglinde Alexandrine Stephanie Thyra (b. 23 August 1917 – d. 23 March 2009), married Hans Reinhold (b. 20 November 1917 - d. 2002) on 12 September 1942 in Potsdam. They had one child before divorcing in 1949:
Manfred Reinhold (b. 13 February 1943)
Friedrich Karl Viktor Stefan Christian (b. 13 March 1919, Jagdschloss Glienicke – d. 19 June 2006, Mallorca), married Lady Hermione Mary Morton Stuart (2 March 1925-2 September 1969)[4] and secondly Adelheid von Bockum-Dolffs (born 16 September 1943).
Death
He and his wife were great lovers of riding and horses, and he was considered one of the best horsemen in Germany.[3] The couple spent most of their time raising and training horses at their Mecklenburg estate, as well as at their estate at Glienicke Castle near Potsdam.[3] He and his wife were great social favorites, and Friedrich was popular with the German people.[5]
On 5 July 1927 at age 35 at Lucerne, Switzerland, Frederich Sigismund fell from a horse.[3][5] He was riding in an international tournament; while doing a difficult jump, he fell and his foot got caught in a stirrup.[3][5] Before he was able to free himself, the horse trod his chest multiple times, breaking five ribs and causing other injuries.[3] He was rushed to a nearby hospital, where he died the following day from his injuries.[3]
