Bloody roots of the classic murder mystery revealed

Multi-award-winning crime fiction writers Kate Summerscale and P D James put on an amusing double act at The Independent Woodstock Literary Festival yesterday, considering their topics were throat-slitting, bludgeoning and hanging.

James pointed out that Summerscale's real-life Victorian murder mystery set the template for the novels of the 1930s, the so-called golden age of crime fiction. The Road Hill House case contained a big house, a closed circle of suspects – the murder had to have been a member of the household – and a multiplicity of motives and clues. "And there's a sexual undertone, more than you get in Agatha Christies," James added with glee.

Her fictional detective Adam Dalgliesh, is also a poet but James admitted he has only ever provided one example of his supposed work, a juvenile poem at that. She revealed she had the idea of asking W H Auden to write the Dalgliesh poems. Sadly the poet died before his response could be recorded. "Perhaps he was murdered," mused the chair, John Walsh.

Dame Phyllis also revealed that "the thing that obsesses my dear readers" is the car journeys Dalgliesh makes. "They write to me saying that 'he couldn't possibly have stopped at a layby on that road' or, 'I don't understand why he doesn't take the A40.'"

Walsh recommended James's new novel, The Private Patient, despite what he described as it's "central implausibility" – who on earth would want to kill a journalist?

Another dame, Ann Leslie provided a possible answer. Judging by her indiscreet anecdotes, if Leslie had been found slaughtered in a locked room, Princess Diana, Germaine Greer and Bill Clinton would have been in the frame. Not to mention assorted warlords and terrorists. She spoke of how her designation caused troubles for her interpreter in the Middle East, because, he said: "In the Arab world, women don't have honours unconnected with a man." The interpreter finally plumped for Sheikha, which just led mystified warlords to say "who is your husband?". Leslie has been a journalist for 46 years, but her memoir Killing My Own Snakes is her first book. "Matthew Parris churns out books like a bulimic throwing up his supper," she said, mystified. Other highlights of her career included being flashed at by Salvador Dali, who, after asking her if she would like to see his "divinity", revealed "a shrimp and two peas".

On Friday night the military historian Richard Holmes was placed in the unusual position of describing the character flaws (and of course the brilliant gifts) of the first Duke of Marlborough and his tempestuous Duchess, Sarah, to their descendents, the Marquis of Blandford and Lady Henrietta Spencer-Churchill. The latter ruefully admitted that both sets of characteristics had been handed down in abundance.

The setting was a dinner in the Orangery at Blenheim Palace, described by Holmes, with the appropriate gesture, as "two fingers up to Louis XIV". Marlborough's victories tipped the balance of power away from the French in the War of the Spanish Succession, and Blenheim was England's grateful reward to the general. It turns out the Duke also had a keen eye for interior design; during his research, Holmes found many letters to the Duchess saying, in effect: "Big battle tomorrow. By the way, I found a wonderful man to do the tapestries." After his glory years the Duke suffered a series of strokes and died, Blenheim still unfinished.

It was a warm and witty portrait of a man whom Holmes came to love for his human qualities as well as his great military victories.