Over the past few years, the image of George Bush as a Roman emperor, dressed in toga and laurel wreath, has been a hard one for his opponents to resist. But even after the bombing of the UN building in Baghdad, things have not gone as badly for him in Iraq as they did for the Romans. For 600 years, the dominant superpower of the ancient world sought to pacify the region – and all for nothing. The details of the various disasters that befell the Roman invaders are the stuff of Paul Bremer’s nightmares. One emperor was killed; another, taken prisoner, was used as a footstool and then stuffed with straw. The most disastrous expedition of all, however, was the first, in 53BC, which led to the loss of 30,000 men and the head of its commander. This gory trophy was presented to an actor for use as a prop in a tragedy – the perfect illustration of how nemesis follows hubris.