George Walden reviews "Opium and Empire" by Richard Grace, which focusses on the origins of Jardine, Matheson & Co., the British firm run by two Scottish traders Jardine and Matheson. This firm was at the centre of the trade in opium carried out on the black market in China using opium brought from India. It paid for the shipping expenses to take tea and silks brought back in the British market. The confiscation of a shipment of opium in Canton, China, by a Chinese Commissioner led to the first of the opium wars. This ended with the Treaty of Nanking in 1842 negotiated by Foreigh Secretary Palmerston giving Britain possession of the island of Hong Kong. It was the long history of such depredations, including the Japanese invasion in the 1930's that led to the nationalism and rise of Communists led by Mao in China by 1945.