Every morning, as many as 20,000 people flock to Tiananmen Square to join the vast queues of pilgrims, often stretching a kilometre long, at the entrance to the tomb of Mao Zedong. Almost 30 years after his death, Mao remains the sacred symbol that China dare not touch. His massive portrait still looms above the entrance to the Forbidden City. His face is on every banknote in the country. Yet while he continues to be worshipped in China, a shocking new book has concluded that Mao was the bloodiest mass murderer in history, a sadistic thug who enjoyed torture and was willing to sacrifice half of China's population for his dream of global domination. The book estimates that Mao caused the deaths of 70 million people in peacetime, making him a far worse killer than Hitler or Stalin. It portrays him as a sociopath who loved killing and allowed millions of peasants to starve to death while he exported food to pay for his nuclear weapons; a man whose legendary achievements in the Long March were an invention; a man who turned China into a cultural desert of misery and violence, while maintaining dozens of luxury villas and a troupe of female sexual partners. China's rulers have acknowledged that Mao made some "serious mistakes," but only "in his old age." And they continue to praise him lavishly, decades after his death.