High Quality Content by WIKIPEDIA articles! Prince Friedrich Georg Wilhelm Christoph of Prussia (19 December 1911 20 April 1966), a.k.a. in England as "Mr. Friedrich von Preussen", was the son of Crown Prince Wilhelm of Germany and Duchess Cecilie of Mecklenburg-Schwerin. On 30 July 1945, he married Lady Brigid Katherine Rachel Guinness, daughter of Rupert Guinness, 2nd Earl of Iveagh, at Little Hadham, Hertfordshire. They had five children: Being a descendant of Sophia of Hanover and having rights under the Act of Settlement 1701, as amended by a 1705 Act, Prince Frederick was naturalised as a British citizen in October 1947 under the name Mr. Friedrich Von Preussen. 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. It is therefore doubtful whether he should have been styled in England as a Prince after 1947 (as distinct from any naming practices in Germany where titles are incorporated into names). In turn, his children's claims to be princes or princesses, and their usage of royal titles, is open to question.