Prince Frederick of Prussia, 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.
Background
On 30 July 1945, he married Lady Brigid Katherine Rachel Guinness, daughter of Rupert Guinness, 2nd Earl of Iveagh, at Little Hadham, Hertfordshire. 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:
James Henry Timothy Tollemache (son of Timothy Tollemache, 5th Baron Tollemache) on 10 May 2014.
Career
Prince Frederick Nicholas (German: Friedrich Nikolaus of Prussia (born 3 May 1946) married the Honorary Princess Beatrice Victoria of Prussia (born 10 February 1981)
Princess Florence Jessica of Prussia (born 28 July 1983) married the Honorary 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 (nee Blahova) (born 28 December 1947) on 2 January 1979.
Tatiana Brigid Honor von Preussen (born 16 October 1980) married Philip Alan Womack 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, (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) 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)
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 Acting of Settlement 1701, as amended by the Sophia Naturalisation Acting 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 United Kingdom as "George Mansfield".
This naturalisation 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 1917-1932, 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, 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.