Robert Byron By James Knox

Don't forget the Fortnum and Mason saddlebags: D J Taylor recommends short voyages only with this flamboyant traveller

Let us, for the sake of particularity, consider a specimen year in the life of Robert Byron: traveller, "wit", dandy, homosexual, controversialist and general ornament of English upper society in the decade before the Second World War. The year 1928 begins with our man sequestered at the family house in Savernake Forest compiling his first book, an account of his recent Greek travels entitled The Station. This done, he takes off on a tour of Spain in a friend's Bentley. Back in England he busies himself with freelance work but has the time to attend Evelyn Waugh's wedding to his first wife Evelyn Gardner. Waugh presents him with the manuscript of Decline and Fall.

The summer marches on. There is a trip to Austria, where his parents are now living, followed by a series of visits to Czech country houses, where six-course dinners are served up on silver plates. Back in England again, having rounded off this tour of Mitteleuropa with six weeks in Vienna, he buckles down to his next opus, The Byzantine Achievement. Relaxation is provided by such standard period diversions as a spoof wedding party staged by the Bright Young People at the Trocadero, and an invitation to a houseparty at Lord Redesdale's country pile, of which his hostess, Nancy Mitford, fondly remarks: "Isn't Robert simply killing?"

Dead at 35 on his way to a war-time posting in the Middle East, Byron (1905-41) lived most of his life in the somewhat orchidaceous atmosphere sketched out above: a world of German sightseeing with "Bobo" (Unity Mitford) and her "delicious Stormies" (stormtroopers), endless foreign travel and passionate disagreements about architecture. The characteristic Brideshead-era perfume that rises from James Knox's 500 or so meticulous pages is frequently so strong as to be overpowering - "What about the workers?" the reader continually wants to shout out, or "My dad lived on a council estate!" - and yet the gilded trifler label, which can be hung around the neck of so many of Byron's contemporaries, obstinately refuses to stick.

One of the great merits of this biography, in fact, is its emphasis on the extreme fluidity of early 20th-century social arrangements. Eton and Oxford-educated he may have been, and committed Savoy luncher he later became, but Byron's background (he was no relation to the poet) was far from promising, and he spent much of his short life chronically hard up. Like several of his fast friends - the most obvious examples are Evelyn Waugh and Anthony Powell - he was essentially a middle-class boy with his way to make in the world. This encouraged a hard-headed attitude towards his work, and also, you imagine, a wariness in the company of grander and better-connected friends.

Nevertheless (as with Waugh, Powell & co), the aristocratic influence can hardly be discounted. Early excursions to such promising sites for the architecturally minded traveller (Byron's professional persona) as Mount Athos were effectively underwritten by grandee chums. Michael Parsons, 6th Earl of Rosse, for whose younger brother Desmond he nurtured a decade-long passion, was a notable patron. The Athos trip of 1927, undertaken with David Talbot Rice, Gerald Reitlinger and Mark Ogilvie-Grant, involved a cortège of pack-mules laden with Fortnum and Mason's saddle bags stuffed with jars of chicken in aspic, a soda siphon, easels, photographic equipment and hold-alls.

The modern travel-writing enthusiast, noting Byron's determined and opinionated progresses around the Near East, weighed down with expensive baggage and glamorous friends, may well be reminded of someone else; and that person would be Bruce Chatwin (significantly Chatwin wrote an introduction to a 1981 reprint of Byron's The Road to Oxiana). There is the same flamboyance, the same extremes of personality, in Byron's case, as Knox shows, often flaring up into outright belligerence. The scholarly editor of the Oxford Persian Survey once received a letter from his contributor that ran "I warn you quite frankly that if this chapter is altered in any way I don't like after I have passed the final proof, I shall put the matter in the hands of a solicitor." Anthony Powell remembered his friend spending a night in the cells after a punch-up in a cinema queue. The sense of a man whose temperament is always spilling over into his aesthetic judgments is occasionally a bit too strong for comfort, and Knox quotes a wonderfully insolent description of Tehran: "that vile stinking hideous intrigue-ridden pretentious vulgar parody of a capital."

The bright promise of the 1920s extended to the end of the next decade. Jaunts to China, Persia, Russia and India alternated with Home Front guerrilla warfare on behalf of the Georgian Society. Personal life, meanwhile, ebbed and flowed. By the late 1930s ailing finances had forced him to take a job as an oil industry PR man; his beloved Desmond died of Hodgkin's disease at the tender age of 26. In 1938, as a fervent anti-Nazi, he accompanied his friend Bobo to Nuremberg, reluctantly raising his arm to salute the Führer (and nearly getting his fingers taken off, such was the pace of Hitler's approach) and leaving a choice vignette of Lord Redesdale searching patiently for his wife's darning needle in a hotel lobby crammed with Nazi top brass.

Diligently researched and neatly written, James Knox's biography is best read in small doses, as the force of the subject's personality can sometimes be a shade oppressive. As for the legendary wit, perhaps the most savage and character-defining thing that Byron ever said goes mysteriously unreported. Anthony Powell claimed once to have overheard someone tediously enquire what he would like best in the world. Byron snapped back: "To be an incredibly beautiful male prostitute with a sharp sting in my bottom."