Prince Frederick of Prussia (1911–1966)

Prince Frederick of Prussia (German: Friedrich Georg Wilhelm Christoph von Preußen; 19 December 1911 – 20 April 1966), also known as "Mr. Friedrich von Preussen" in England, was the fourth son of Crown Prince Wilhelm of Germany and Duchess Cecilie of Mecklenburg-Schwerin. By renouncing his German citizenship in 1947, he relinquished his place in the line of succession to the former German throne.

On 30 July 1945, he married Lady Brigid Katherine Rachel Guinness, daughter of Rupert Guinness, 2nd Earl of Iveagh, from the famous brewery family, at Little Hadham, Hertfordshire. They had five children, fifteen grandchildren and seven great-grandchildren:

• Prince Frederick Nicholas (German: Friedrich Nikolaus) of Prussia (born 3 May 1946) married the Hon. Victoria Lucinda Mancroft (born 7 March 1952, daughter of Stormont Mancroft, 2nd Baron Mancroft) on 27 February 1980 in London and have four children and a granddaughter:
  • Princess Beatrice Victoria of Prussia (born 10 February 1981)
  • Princess Florence Jessica of Prussia (born 28 July 1983) married the Hon. James Henry Timothy Tollemache (son of Timothy Tollemache, 5th Baron Tollemache) on 10 May 2014. They have one daughter:
    • Sylvie Beatrice Selina Tollemache (born 2 March 2016)
  • Princess Augusta Lily of Prussia (born 15 December 1986) married Caspar William Helmore on 19 September 2015
  • Prince Frederick Nicholas Stormont of Prussia (born 11 June 1990)
• Prince William Andrew (German: Wilhelm Andreas) of Prussia (born 14 November 1947) married Alexandra Alsbett (née Blahova) (born 28 December 1947) on 2 January 1979. They have two children and one grandson:
  • Tatiana Brigid Honor von Preussen (born 16 October 1980) married Philip Alan Womack (born in 1981) on 28 June 2014. They have one son:
    • Arthur Frederick Richard Womack von Preussen (born 21 November 2015)
  • Frederick Alexander Henry von Preussen (born 15 November 1984)
• Princess Victoria Marina Cecilie (German: Viktoria Marina Cecilie) of Prussia (born 22 February 1952) married Philippe Alphonse Achache (born 25 March 1945) on 3 May 1976. They have two sons:
  • George Jean Achache (born 8 June 1980)
  • Francis Maximilian Frederick Achache (born 30 April 1982)
• Prince Rupert Alexander Frederick (German: Rupprecht Alexander Friedrich) of Prussia (born 28 April 1955) married Ziba Rastegar-Javaheri (born 12 December 1954, into a wealthy Iranian industrial family) on 5 January 1982 in London, England. They have two daughters:
  • Brigid Elizabeth Soraya von Preußen (born 24 December 1983)
  • Astrid Katherine Rabeéh von Preußen (born 16 April 1985)
• Princess Antonia Elizabeth Brigid Louise (German: Antonia Elisabeth Birgitta Luise) of Prussia (born 28 April 1955) who married Arthur Charles Valerian Wellesley, 9th Duke of Wellington on 3 February 1977 at St. Paul's Church, Knightsbridge, London; they have five children and five grandchildren:
  • Arthur Gerald Wellesley, Marquess of Douro (born 31 January 1978); married (4 June 2005) to former model, now make-up artist Jemma Kidd (born 20 September 1974), fashion stylist and great-granddaughter of Lord Beaverbrook. They have twins and a younger son:
    • Lady Mae Madeleine (born 4 January 2010), twin to
    • Arthur Darcy, Earl of Mornington (born 4 January 2010).
    • Lord Alfred (born 10 December 2014).
  • Lady Honor Victoria Wellesley (born 25 October 1979); married 3 July 2004 (as his second wife) the Honourable Orlando Montagu, younger son of the Earl of Sandwich, and had 2 issue:
    • Walter Montagu (born 3 December 2005); first grandchild of the Duke and the Duchess, then the Marquess and Marchioness of Douro.
    • Nancy Jemima Montagu (born January 2007).
  • Lady Mary Louise Wellesley (born 16 December 1986).
  • Lady Charlotte Anne Wellesley (born 8 October 1990); who attended Oxford University reading archaeology and anthropology. Her day job is at photographer Mario Testino’s studio in London, where she is a producer. On 28 May 2016, in Spain, she married billionaire Alejandro Santo Domingo, uncle of Tatiana Santo Domingo, wife of Andrea Casiraghi.
  • Lord Frederick Charles Wellesley (born 30 September 1992); who attended Eton College.

• Eilers, Marlene. Queen Victoria's Descendants. Rosvall Royal Books, Falkoping, Sweden, 1997. pp.17-18, 124-125, 172. ISBN 91-630-5964-9
• Milani, Abbas. Eminent Persians, The Men and Women Who Made Modern Iran, 1941-1979, Volume 1, Syracuse University Press and Persian World Press, Syracuse, New York, 2008. pp.661-664. ISBN 978-0-8156-0907-0
• His birth was only reported in the Daily Mail 31 December 2014 in a story about the late Duke not meeting his newborn great-grandson. See also "Jemma Kidd's husband becomes heir apparent to the Duke of Wellington after his grandfather dies six months before 200th anniversary of Waterloo" 31 December 2014, retrieved 1 January 2015. The date of birth was reported on the Peerage News group on Google Groups.
• Maung, Carole Aye (5 September 1997). "Our Auntie Diana". The Mirror. Retrieved 15 June 2013. 

He was studying at Cambridge, living incognito under the name of Count von Lingen, when war broke out in September 1939. He was arrested and interned in May 1940. He was held in England for several months, then sent to internment camps near Quebec City and, soon afterwards, Farnham, Quebec. In both camps, he was elected camp leader by fellow inmates.

Being a descendant of Sophia of Hanover, and having rights under the Act of Settlement 1701, as amended by the Sophia Naturalisation Act 1705, he was naturalised as a British citizen in October 1947 under the name Mr. Friedrich von Preussen (having also been known during residence in the UK as "George Mansfield"). This naturalization was controversial to some, and his status and a subsequent claim for compensation was debated in parliament and the law courts until 1961. In the period 1917-32, it was settled that a person who had a foreign title would normally undertake to relinquish it before he/she could receive a certificate of British naturalization (like the Princes von Battenberg became the Mountbatten family), and no exception was made in the case of Mr. Friedrich von Preussen.

He was the owner of Schloss Reinhartshausen at Erbach, Rheingau. While staying there in 1966, he went missing and was found two weeks later, having drowned in the Rhine, whether suicidally or accidentally could not be determined.