ONE morning in December 1824, the Duke of Wellington received an unpleasant letter. 'My Lord Duke,' it began, 'in Harriette Wilson's Memoirs, which I am about to publish, are various anecdotes of Your Grace which it would be most desirable to withhold, at least such is my opinion. I have stopped the Press for the moment, but as the publication will take place next week, little delay can necessarily take place.'

The letter, signed by one Joseph Stockdale, a pornographer and scandal-monger, was a naked attempt at blackmail. The Duke was a field marshal, cabinet minister, national hero, husband and father, while Harriette Wilson was a famous London courtesan past her prime, then living in exile in Paris. Wellington was being asked to pay money to be left out of her memoirs.

His response is famous: 'Publish and be damned]' And they did. Through 1825 the memoirs appeared by instalments, each with a dramatis personae listing the notables named in order of rank - 'Dukes: Argyll, Beaufort, de Guiche, Leinster . . .' and so on through earls and viscounts down to humble esquires.

London society was thrilled and scandalised. Half the aristocracy was named in the book, and painted in a most unflattering light. The memoirs went through 31 editions in one year; excerpts were pirated and sold as illustrated broadsheets and French and German editions quickly appeared to delight the gossips of the Continent.

Stockdale, the impresario, and Wilson, the scarlet woman, were said to have made pounds 10,000 from the enterprise, but their good fortune did not last. Stockdale was soon ruined by libel suits, while Harriette was down on her luck again within a few years, and died in obscurity.

What did her memoirs reveal about the Duke? He was, she wrote, her 'faithful lover, whose love survived six winters'. He was 'my own Wellington, who sighed over me and groaned over me by the hour, talked of my wonderful beauty, ran after me . . .' and he was 'my constant visitor', a 'modern Bluebeard', 'my old beau'.

Her story was that they became lovers in 1805, not long after he returned from India a general and a minor celebrity (and not long after he was married). They had a halting relationship for some years, interrupted by the Peninsular War, and eventually drifted apart. There was one last meeting, in Paris in 1814, when they swapped memories and he stopped her laughter by 'kissing me by main force'.

She felt she and Stockdale had acted fairly by giving him the chance to buy his way out of her book - others, she wrote, had seized the offer with gratitude - and she did not spare him in print. Not only was he named among her throng of clients, he was also mocked and belittled for his lack of charm and style. The Duke, she said, was 'most unentertaining', 'very uphill work', and 'in the evenings, when he wore his broad red ribbon, he looked very much like a rat-catcher'.

Elizabeth Longford, biographer of Wellington, dismisses much of Harriette's story as 'choice lies', pointing out errors of detail and chronology which render some of the scenes impossible. But she detects a germ of truth. Wellington was a lady's man caught in a loveless marriage; he is known to have patronised the procuress in Berkeley Street, who acted for Wilson; and the dialogue in the memoirs, it was noted at the time, accurately captures the Duke's speech.

Although Wellington's answer to Stockdale's blackmail letter does not survive in his own hand, there is no reason to doubt he used those famous words. But his stance was less bold than they suggest, for he also threatened to sue 'if such trash is published'.

The threat was ignored but the Duke did not issue a writ, perhaps because others got there before him, or perhaps because there was too much truth in what Wilson wrote. Either way, his reputation did not suffer and he was not forced to resign for reasons of security or hypocrisy or anything else. On the contrary, he remained the nation's hero and went on to become prime minister.

Real Life, page 24

(Photographs omitted)