"Patrick Leigh Fermor," by Artemis Cooper Surprise is the keynote of the best travel writing. The travel writer should be knowledgeable but not an expert, open in mind and body to the unforeseen twists of serendipity. But what we most require from travel writing, as opposed to mere guidebooks, is that elusive quality Nick Carraway defined as "romantic readiness." Few 20th-century figures combined these traits in a more appealing package than the English writer Patrick Leigh Fermor, Paddy to his many friends, who died in 2011 at the age of 96. One of these was Diana Cooper, a famous beauty who turned up in the fiction of Evelyn Waugh. Now Artemis Cooper, her granddaughter, has written an affectionately intimate, informative and forgiving biography of Diana's complicated friend. An Adventure By Artemis Cooper New York Review Books. $30. Like Kipling, another great travel writer, Fermor was born into a family molded by colonial India. Like his idol, Byron, whose slippers ("made of thin red tooled leather with yellow silk uppers and turned-up toes") he jubilantly tracked down in Missolonghi, he was also a hero of modern Greece. At 69, just for the hell of it - and because Byron had done so - Fermor swam the Hellespont, confident that he "had beaten all records for slowness and length of immersion." Farmed out to a family in the English countryside during World War I, Fermor first met his father, a geologist based in Calcutta, when he was about 6, but was much closer to his vivacious, artistic mother. "Not an easy child to handle," according to Cooper, young Paddy was expelled, twice, from a prep school for science and engineering, sandwiched around a happier stint at an "experimental school for difficult children" where staff and students performed eurythmics in the nude. He briefly considered a military career, then sold silk stockings door to door to pay the rent. But he found the wild parties of the "Bright Young People" chronicled in Waugh's "Vile Bodies" more to his taste. Fermor's inventive "solution to the Paddy problem" was to walk across Europe, as simple as that. Armed with little more than a rucksack and a pocket volume of Horace, he began his trek in Rotterdam in December 1933 and headed east, bound for Istanbul. In his buoyant enthusiasm, Fermor can seem a kind of English Kerouac, learning "how to survive," as Cooper notes, "on the road." What rendered the walk more piquant was its timing, as a watershed both for Fermor, about to turn 19, and for Europe, on the brink of World War II. Much of the dynamism of Fermor's Proustian travelogue "A Time of Gifts," written four decades later, comes from its divided point of view, the perceptual gap (Fermor thought of calling the book "Parallax") that separates the bright-eyed student from the mature writer who knows the grim business that followed. Quick to enlist when Britain entered the war, Fermor was eventually assigned to undercover intelligence work in occupied Crete. His taste for adventure culminated in a daring plan - more "Mission Impossible" than part of any coherent strategy - to kidnap a German general and spirit him off the island. Fermor recalled how General Kreipe, watching the sun rise above Mount Ida, quoted the opening of one of Horace's odes, which Fermor, from his "private anthology" of memorized poetry, completed - a bond of civility amid the carnage. Back in London, Fermor took up a life of writing interspersed with travel. He devoted two books (one of them his only novel) to the Caribbean and two to Greece, where he built a seaside house with his wife, Joan. And then there was his account, in three volumes and still incomplete at his death, of his great walk. Cooper doesn't shy away from what she gingerly calls "the interplay of Paddy's memory and his imagination." Did he really cross the Great Hungarian Plain on horseback? Well, he may, as she put it, have "smudged the facts a little," but he explained that he "felt the reader might be getting bored of me just plodding along." And what about that paperweight in the Bosnian émigré"s room in Vienna? Fermor admitted that it "was actually something he saw many years later in an antique shop in Salonika - "but it fitted so perfectly." " If, as Cooper remarks, "the magpie mind adds details freely" - one thinks in this regard of Fermor's friend and fellow embroiderer Bruce Chatwin - Fermor mostly got the larger story right. Christopher Benfey teaches at Mount Holyoke College and is the author, most recently, of "Red Brick, Black Mountain, White Clay."