See his autobiography, Those 20th Century Blues (1990), Tippett on Music (1995), and biography by M. Bowen; study by E. W. White (1979).
Family and Court Connections
His maternal grandmother was a sister of the 13th and 14th Earls of Pembroke and Montgomery, and a daughter of the Rt. Hon. Sidney Herbert, 1st Baron Herbert of Lea, the half-Russian younger son of the 10th Earl of Pembroke, and a good friend to Florence Nightingale.
Sir Michael Duff was a godson of Mary of Teck (queen of King George V), and a close relation of several aristocratic families. Among his relatives was his maternal aunt, Lady Diana Cooper (nee Manners). Exceedingly handsome and with the courteous manners of a true gentleman, he was famed as a host and raconteur. He inherited the idyllic 1,000 acre (4 km²) Welsh estate of Vaynol (occasionally spelt as 'Faenol'), the slate of which was the principal source of the family's wealth. Surrounded by the estate's seven mile stone wall, the Duffs lived in the nineteenth century Vaynol New Hall. (The medieval Vaynol Old Hall, also on the estate, was lived in by the farm manager and later the estate manager.) Sir Michael frequently played host to members of the Royal Family (of whom he was a favourite), the aristocracy, gentry, Hollywood stars and members of Society.
On reaching his maturity in 1928, Sir Michael assumed the additional surname of Assheton-Smith, only to renounce it again in 1945. He served as Mayor of Caernarvon, High Sheriff and Lord Lieutenant of both Caernarvonshire and of Gwynedd. He was a practical joker, one of his favourite pranks being to dress up as Queen Mary and pay surprise visits to friends - until he bumped into the Queen herself in a neighbour's hall. He also wrote a light novel, The Power Of A Parasol.
He married first 5 March 1935 Hon Joan Millicent Marjoribanks, dau of Baron Tweedmouth. Marriage annulled 1937. He married second Lady (Alexandra Mary Cecilia) Caroline Paget (died 1973) eldest dau of Charles Paget, 6th Marquess of Anglesey and his wife Lady Marjorie Manners, eldest daughter of the Henry Manners, 8th Duke of Rutland. They adopted a son, Charles David Duff (b.1950), who became a theatre historian.
A documentary screened on BBC Two Wales in 2005 ('Faenol: Secrets Behind the Wall') featured Charles Duff discussing his childhood, the bisexuality of both his adoptive parents, and the mystery of his true parentage. He did not inherit the estate, and when it was sold all the records were burnt, so compounding the mystery. In another interview for the BBC (Wall Of Silence, BBC Wales website) Charles said of Vaynol: "It was a place of great conviviality and energy and joy." However, by the time Charles was in his teens, Sir Michael had come to believe that marriage and adoption had been a grave error, and according to Charles "he started to demonise both my mother and myself." Although appearances were maintained, neither could then do much right in Sir Michael's opinion. By this time the house and estate were also in decline. (Before the Second World War there had been 17 gardeners.)
The Vaynol estate, in northern Wales, close to the Anglesey estate at Plas Newydd, passed out of Duff family hands, the last main portion including the demesne within the walls being sold off in 1984. This came into the family via Mary Assheton-Smith, niece and heiress of the famous squire Assheton-Smith, the celebrated foxhunter.