It was at the beginning of the war that the two correspondents first crossed paths, at a regimental ball in Derbyshire. Patrick Leigh Fermor was a young officer in the Intelligence Corps and the ravishingly beautiful Deborah Mitford, aged 20 (the youngest of the Mitford sisters) had just become engaged to Lord Andrew Cavendish and had eyes for nobody else. “They seemed to be sleep-­dancing,” Leigh Fermor recalled, “utterly rapt, eyes shut as though in a trance.” She noticed him soon afterwards, however, at a fancy-dress party in London when he arrived costumed as a Roman gladiator armed with net and trident. But the real friendship began in 1954 when Deborah, now the Duchess of Devonshire, invited Leigh Fermor to stay at Lismore Castle in Ireland. By this time he had written two books and was a war hero, awarded the DSO for his leading role in capturing Heinrich Kreipe, the German commander in Crete, an extraordinarily daring exploit later written about and filmed.

In Tearing Haste is the correspondence between Deborah Devonshire and Patrick Leigh Fermor, spanning a period of over 50 years, full of gossip and jokes and the details of daily life, she in England running her great house, Chatsworth, he in his small house in the Peloponnese. Both are consummate performers; both enjoy life, are infinitely curious, and love to be amused; neither wishes for profound personal revelation, but they know many of the same people, share a similar, faintly eccentric sense of humour, as well as (in her case particularly) a robust common sense; they both take pleasure in glamorous society while at heart cherishing the ideal of a simple, almost rustic existence; both are deeply attached to the natural world. There are differences, of course: he, a professional writer of distinction, is widely travelled and read, whereas she only occasionally leaves England and claims to loathe reading. “How I HATE books,” she unrepentantly declares.

There are many more of his letters than of hers, and they are remarkable. Striding across Europe and beyond, he sends back vivid accounts of his journeys in France, in Italy and Greece, Turkey, India, South America and the Middle East. Much of this is travel writing of the highest order, combining an absorbing personal narrative with brilliantly observed visual detail. Here, for instance, is a passage about his stay in a tiny village in Provence, where in order to finish a book “[I] scribbled all day .?.?. in the priest’s leafy garden overlooking a forested valley along which flowed a swift and icy river with deep green pools dappled with the shadows of leaves where I splashed and floated between paragraphs for hours among the dragonflies.” There are long passages detailing tremendous expeditions through the Andes, over the Pyrenees, of immense treks through the Pindus Mountains in the north of his beloved Greece. One of the most memorable is a terrifyingly vivid account of this extraordinary man’s successful attempt, at almost 70, to swim the Hellespont. “It seemed quite easy at first, the landmarks .?.?. changed places with heartening speed, and the dreaded current didn’t seem too strong. A huge Russian tanker, Bogomiloff, loomed from the north leaving a strong wash behind it?.?.?.”