Christian VII of Denmark (1749-1808) was insane throughout his long reign. The royal physician, Johann Friedrich Struensée (1737-72), usurped his power. In 1771 the King appointed him Privy Cabinet Minister. Struensée revolutionized the whole administration of the Danish-Norwegian kingdom and had an adulterous relationship with the Queen, Caroline Mathilda, George III's sister. In January 1772 he was arrested, sentenced to death for lese-majesty and executed. During his confinement, he wrote a memoir on the King's condition, which he considered to be caused by, or the effect of, masturbation. In 1906 Christiansen interpreted it as a case of dementia praecox, i.e. schizophrenia. It is now suggested that Christian's insanity, like that of George III (his cousin), might have been due to porphyria - the 'royal malady', possibly inherited through his mother, Princess Louise of England or his father, King Frederik V, who died from an illness which retrospectively resembles a case of porphyria.