The first glimpse, and the rest of the story

Wilfred Thesiger would disapprove strongly: barely three years after his death, he has already attained mythical status as one of the greatest explorers of the 20th century. And, as with so many contemporary icons, it is not immediately obvious why. At first glance, he appears to be a self-obsessed Old Etonian with a chronic case of wanderlust, responsible for a handful of travelogues and some workmanlike black-and-white photographs of handsome boys from the remoter corners of the Earth. And yet, closer inspection reveals a complex and relevant global figure whose busts and portraits decorate the hallowed halls of the Royal Geographical Society and the Travellers Club. His photographic archive has pride of place in Oxford's Pitt Rivers anthropological museum and his early books Arabian Sands and The Marsh Arabs have never gone out of print.

Wilfred Thesiger: The Life of the Great Explorer is Alexander Maitland's weighty justification for Thesiger's "greatness". It comes hot on the heels of his photographic retrospective Wilfred Thesiger: A Life in Pictures , which met with a mixed critical reception. But, while its photographic reproductions and selection of images felt tired, that book contained a pearl of an introductory essay by Maitland that left the geographical community hungrier than ever for the biography that he had been reportedly writing for years.

Maitland is the expert on Thesiger, and this book is his masterpiece. A certain amount of publisher's hype has revolved around "lifting the lid on Thesiger's sexuality", but - quite apart from being the biggest non-story in exploration - this deflects attention from the real issue, which is why Thesiger is such an enigma in the first place. Maitland, who knew him well, seems to think that part of the answer may be that he was simply born in the wrong era. Thesiger famously detested the internal combustion engine, claiming that it "robbed the world of its diversity", and yet, Maitland reveals, he once told Eric Shipton, the mountaineer, that "gentlemen don't drive". Thesiger later claimed that this was a joke at his own expense (he could drive, but he was convinced that being properly dressed and from Magdalen College, Oxford, made him a "gentleman") and Maitland graciously believes him. Robin Hanbury-Tenison, another great explorer of the 20th century, captures the tensions between outer and inner Thesiger perfectly:

"I thought him an archaic figure with excessively reactionary views. Only later did I realise that behind the facade of the British upper class lay a passionate environmentalist, whose radical views on globalisation, the misuse of the planet... have now entered the mainstream." Thesiger also had an innate understanding of human communities and took deep delight in living among tribal people, particularly in the Arab world. Communicating this acquired knowledge was the explorer's legacy, and Maitland conveys this in a detailed and fascinating manner.

At times, Maitland's infectious enthusiasm for his subject appears to get the better of him. In his chapter on the Marsh Arabs, Maitland maintains that Thesiger's time among the Ma'dan, coupled with the information he gathered on his journeys among them, "raise him far above contemporaries and predecessors alike", including Gertrude Bell and Freya Stark. Given that Bell visited the marshes 45 years before Thesiger, and Stark photographed the region immediately before the Second World War, Maitland's statement is contestable. To claim that Thesiger's photographs are of "matchless brilliance" is similarly over the top, though, to be fair to Maitland, he is elsewhere brutally frank both about Thesiger's character - he says he had a "vile temper" and was "temperamental and prone to moods of black depression" - and his abilities as a writer.

This balance is one of the many strengths of Maitland's approach. In later years, Thesiger was to deny that he had received help in the preparation of Arabian Sands , insisting "it was my book and I wrote it" - but there is much truth in Gavin Young's comment that Thesiger's books were "written by committee". And Maitland is excellent, if blunt, in revealing the layers of tension between Thesiger and his friends (particularly Gavin Maxwell and Valentine ffrench Blake), and in his running analysis of Thesiger's Lawrentian relationship with his mother, Kathleen.

Maitland introduces his biography with a wonderful quotation from Thesiger, worth reproducing in full. Thesiger, musing with his putative biographer over how the book should start, suggests: "Even now, after so many years, I can still remember Wilfred Thesiger as he was when I first saw him. The rest is up to you." The rest, of course, is history, and Maitland has done a superb job in pulling together the diverse threads of a life whose significance goes well beyond the geographical community.

Nick Smith was until recently editor of Geographical , the magazine of the Royal Geographical Society.