You write the reviews: Hadrian: Empire And Conflict, British Museum, London

Hadrian: Empire and Conflict, the second of four major exhibitions at the British Museum on rulers who shaped the world in which we now live, presents us with a problem. What are we to make of an admirer of Greek culture who, shortly after taking office, withdrew Roman troops from Mesopotamia, commissioned innovative and beautiful buildings and honoured his male lover with evocative statues, but perpetrated acts of genocide against the Jews?

This question is provoked, but not directly answered, by this exhibition which seems more concerned with what preoccupies most leaders, namely, their image. We see Hadrian as a young man in the guise of Romulus, the founder of Rome; as a naked god; and as an implacable general, quashing underfoot a puny captive. But we also see what some of his Jewish victims left behind when they sought refuge in desert caves: mirrors, bowls, a straw basket.

Hadrian was a descendent of Roman soldiers who had settled in Spain nearly three centuries previously. Although this made him an outsider, he had also lived in Rome and held important political and military posts before becoming emperor. This enabled him to see the Roman empire from the inside – the senatorial view – and from the outside – from the perspective of a provincial; a dual vision that enabled him to become the first emperor to surrender territory that he considered untenable, and to concentrate on consolidating the territories that remained. This remarkable decision prolonged the empire's span, but would hardly have been welcomed by the Roman patricians.

Neil MacGregor, the director of the British Museum, writes in his foreword: "Not only can the past help us better to understand the present, but the present can also inspire a fresh look at the past": we can see how the surrender of territory now occupied by Iraq might be relevant today, but how can the present change our view of the past?

Hadrian's ferocious suppression of the Jewish revolt shows that genocide against Rome's enemies was not regarded as a crime, but as a cause for victory parades, and that Hadrian was a much more complex and flawed leader than the exemplar of wisdom he was once thought to be.

But it also contains a warning for us today: our idealisation of "great leaders" is dangerous, and can, if we abandon our personal responsibilities as citizens, lead to great crimes.

To 26 Oct (020-7323 8181; www.britishmuseum.org)

Paul Crichton, consultant psychiatrist, London

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