The discussion of social class in Britain is fraught with humbug and the term middle class defies definition

The discussion of social class in Britain is fraught with humbug and the term “middle class” defies definition. We all, even supposedly detached historians and sociologists, have a vested interest, which warps our judgement. Quest and pessimism entwine, taking me back to that other monumental 12-chapter epic, Levi-Strauss’s Tristes Tropiques, which Thubron’s magisterial threnody matches.Justin Wintle’s biography of Aung San Suu Kyi appears next year. Between them they poke away at individual faiths, at faith itself.Centuries before the opening of the Suez Canal in 1869, the globalising Silk Road was irreparably frayed. Only Ismail Khan, Shi’ite leader and former main player in Afghanistan’s internecine woes, is a known quantity But Khan, too, is diminished: a superannuated warlord For once, no illuminating conversation flows So it is back to Thubron’s phantasmic Sogdian trader. His witnesses are mainly losers: victimised professionals, underground artists, oppressed women These are the people who needs must speak to him.

So he journeys onward through northern Iran (a fetid police state as much as a theocracy) and southern Turkey (the Kurdish question there) until he reaches Antioch, once an eastern outpost of ancient Greece, thereafter home to an incipient Christianity.Thubron takes it all in. Yet Thubron refers to “the Mongol Peace”: they crushed the Assassins, the al-Qa’ida of those days, to the glee of Christendom. Westwards through the awesomely barren Tarim Basin, he traces a once buoyant Buddhism. Well before he reaches Kashgar, shaded by the Pamir mountains, Islam rises with the tyrannised Uighurs. In Kyrgyzstan, then Uzbekistan, an emasculated Islam greets him – suborned by the departed Soviet Union’s secularism.So much of what Wintle half-finds in his journey’s middle reaches was destroyed by the Mongols. The modern Chinese he meets are secularists, their dreams borrowed from America But entering the Gansu corridor, all that evaporates. The way ahead is strewn with destroyed cities, ruined monuments, empty sepulchres: the shell of Samarkand.In defiance of the map’s frontiers, peoples, cultures and faiths only slowly merge into one another.

He travels light: a rucksack full of maps, primers, notebooks, money secreted in an anti-mosquito spray.There is very little by way of clothing, even less of ego – but there is a phantom alter ego that tags along, a Sogdian trader who quizzes Thubron about his motives. From their imagined dialogues it emerges that Thubron’s obsession is chiefly with death. Or is it that too much of the decayed landscapes he traverses has rubbed off on this leathery, erudite explorer, enamoured of legend and fable?Fable thrives in lonely, loveless places. Thubron begins in the heart of old China, at Huangling, site of the supposed tomb of the mythical Yellow Emperor. He progresses to bustling Xian, once Chang-an, capital of the founding Qin dynasty.