There was never one Silk Road - but several. The route chosen by Colin Thubron passes through China, Uzbekistan, Kyrgyzstan, Afghanistan, Iran and Turkey, taking in the most sterile desert on earth (the Taklamakan) and the strife-torn mountain valleys of today's conflicts, as he travels from the tomb of the Yellow Emperor (the mythic progenitor of the Chinese people) to the ancient port of Antioch, by local bus, truck, car - occasionally Landrover, horse or camel. He covers 7,000 miles in 8 months, and confesses that it is the most difficult, complex and ambitious journey he has undertaken in 40 years of travel. The Silk Road is a huge network of arteries and veins, splitting and converging across the breadth of Asia. Chinese silk has turned up in the hair of a 10th-century-BC Egyptian mummy; equally, the tartan plaids of 3000-year-old mummies in the Chinese desert echo those of early Celts. To be travelling the Silk Road, writes Colin Thubron, is to be travelling the history of the world: tracing the passage not just of trade and armies, but of ideas, religions and inventions. Yet - despite the lure of the history - this book is as much about Asia today. Its themes include different Islams (oppressed in China; fervent in Afghanistan and Iran; cautiously monitored in Uzbekistan); contrast (no cities could be more different than ancient Samarkand and modern Teheran); and the way that today's borders are meaningless because the true boundaries are made by tribe, ethnicity, language and religion. Shadow of the Silk Road is a brilliant account of an ancient world in modern ferment.