By Royal Appointment: A Biography of Mary Ann Clarke, Mistress of the Duke of York

Of all the famous mistresses, from Nell Gwynne and Emma Hamilton to Madame de Pompadour and Lily Langtry, Mary Ann Clarke was the most spectacular and the most outrageous. Her career was a rags-to-riches story of a girl from the back streets of Georgian London who rose with premeditated guile to a life of pretentious affluence as the mistress of The Brave Old Duke of York.

A stream of military men fawned upon her to use her influence with the Duke, flattering her vanity and providing the money to finance her reckless extravagance. All was grist to her duplicity, from two Colonels seeking an exchange to an ambitious Colonel aspiring to the rank of Brigadier-General, and a Colonel and a Captain wanting a profitable recruiting levy. For 1000 pounds she placed a devoted admirer in the Commissariat and to her footboy she presented a commission.

When discarded by the Duke in 1806, Mrs. Clarke's fortunes were at a perilously low ebb, but two and a half years later she extended her nefarious practices with spellbinding panache by appearing in the House of Commons to support Colonel Wardle's charge of the misconduct of the Duke of York as Commander-in-Chief of the Army.

For several weeks she was a national sensation. People cheered her in the streets and her wit and effrontery provided the satirists with illimitable scope.

The aftermath of the enquiry was equally dramatic. A timorous government paid £10,000 for the suppression of her memoirs and two successful lawsuits also followed in less than six months.

She died, like Emma Hamilton, in obscurity and comparative poverty, but the achievements of her descendants - George du Maurier, the illustrator and author; Sir Gerald du Maurier, the Edwardian actor; and her great-great-granddaughter, Daphne du Maurier - must surely owe much to the intelligence and vitality inherited from the indomitable girl from Bowl and Pin Alley.