The end of empire has less to do with declining British military and political power than with a worldwide trend towards milder laxatives, according to ground-breaking new Week Ending research. These new findings, destined to revolutionise the study of British colonial history in East Asia, are published exclusively today in the South China Morning Post. Week Ending reached its startling new conclusions after applying its uniquely sophisticated techniques of political and historical analysis to the words of the Qing Dynasty Imperial Commissioner Lin Zexu, shortly after his notorious torching of foreign traders' opium stocks - the gesture which lit the fires of the Opium War and ultimately led to the creation of Hong Kong. 'Is there a single article from China which has done any harm to foreign countries?' he thundered in a threatening letter to Queen Victoria, demanding an end to the opium trade. 'Take tea and rhubarb for example. The foreign countries cannot get along for a single day without them. If China cuts off these benefits with no sympathy for those who are to suffer, then what can the barbarians rely on to keep themselves alive?' Anyone doubting his word should look no further than Her late Britannic Majesty's family medicine cupboard. Like Commissioner Lin's own, and for that matter the medicine chests of Anthony and Cleopatra (yes, that is the Cleopatra of the dowry), it would have contained a quantity of dried Chinese rhubarb root. Rhubarb was valued across the Northern hemisphere as the perfect laxative and stomach remedy. The British would probably not have perished en masse of permanent constipation if supplies of rhubarb had dried up. But there might have been some long-term effects on the empire's health - especially after the root was discovered in the 1920s to be a cure for the 'dreadful tropical scourge' of the colonies, bacillary dysentery. Purges have been as popular in medicine as in politics in China since at least 2700 BC when the extracts of what we Outer Barbarians classify as rheum officianale and rheum palmatum were first described in the Chinese herbals. So it's probably no coincidence that the root of the giant strains of oriental rhubarb became popular in ancient Rome at around the time the Empire was moving towards ever crueller and more arbitrary forms of dictatorship. The Romans called it rha ponticum, because they thought it came from the kingdom of Pontius in Asia Minor. In fact, it was brought there by the Central Asian An T'sai or Aorsi tribe, thought to have won a monopoly from the Han Emperor in the second century BC. Romans knew their luxurious silks came from the mysterious East. But the origins of the humble rha do not seem to have excited the same interest. Hardly surprising, is it? Just because your laxative happens to have come all the way from the slopes of Gansu and Inner Mongolia to Urumqi, and been carried by a bunch of primitive nomads across the freezing steppes north of the Tien Shan mountains, across Kazakhstan, round the northern end of the Caspian Sea and down to your local apothecary doesn't mean you have to think of the stuff as glamorous. We've all heard of the Silk Route. How many people have heard of the Rhubarb Route? Anyway, the point of all this is not to display Week Ending's unparalleled erudition, but to point out that times have changed. The 18th century English apothecary Hayward, who tried to sell locally-grown, Oxfordshire rhubarb by dressing his pedlars up as Turks and passing it off as the real thing, would hardly have bothered today. The fact is we drink Indian tea or even coffee, and lubricate our bowels with senna. The only things we buy from China are cheap toys and goods which could be just as easily sourced elsewhere. Even the opium (which Chinese traders now sell to the British) could be routed more directly from the Golden Triangle. So who needs a barren rock off the coast of China any more? Here, it's yours Mr Tung. Have it back.