Hadrian: Empire and Conflict, British Museum

Hadrian: Empire and Conflict, is the second in a series of four linked exhibitions at the British Museum. The first in 2007 starred China's First Emperor, Qin Shihuangdi and his terracotta warriors.

Then 2009 and 2010 will feature the Persian and Aztec empires of Shah Abbas and Moctezuma. This quartet, explains British Museum director Neil MacGregor, was chosen as exemplars of great rulers who shaped the world in which we live.

Both China's first and Rome's 14th emperors presided over vast territories of lands and peoples. Both reformed the structure of their armies and of their central civil service. They both built walls - to keep people out, to keep people in, perhaps even as statements of territorial rights.

But there is one clear difference between the emperors: no contemporary images of Qin Shihuangdi exist. He remained the invisible centre of his exhibition. The figures were all of his humbler subjects.

Hadrian is everywhere, present on coins and in massive statuary. His subjects, empire-wide, knew him by his officially sanctioned portraits, whether in battledress as a warrior, clad in a priestly or magisterial toga, or naked, as a god, the descendant of Mars.

Hadrian is immediately recognisable by his powerfully bearded face and by his distinctively creased earlobes. There is also on display a statue of Hadrian in a himation, the traditional Greek mantle. Brought to the British Museum from Cyrene in 1861 it seems to show the emperor uniquely as a lover of the arts and of all things Greek.

In preparation for the exhibition the curators became aware of discrepancies. The head was out of proportion to the body and on closer inspection it became clear that they did not belong together. The sculpture had been reconstructed in all good faith to fit the Victorian conception of Hadrian as a peace-loving philhellene.

Each generation creates their own image of a historic figure. Hadrian has been vilified for his decision to draw back from the conquests of his predecessor, Trajan. To some, this seems evidence of weakness, a denial of the tradition of limitless expansion espoused by Augustus, and the first signs of imperial decline and fall. Others have seen him as a far-sighted leader and promoter of diplomatic peace.

Reviewers have noted that the major trouble spots of Hadrian's time (and still of ours), were in Judea/Palestine, the Balkans, Caucasus and Mesopotamia - modern-day Iraq. It is intriguing to note that some political commentators urge modern forces to follow his example and withdraw. But they do not suggest that we follow the Hadrianic tradition of ruthless repression and destruction of Jerusalem as a solution to the tensions of the Middle East.

The exhibition shows that for more than 20 years Hadrian ruled and held together an empire whose territories covered parts of three continents, whose borders stretched from Scotland to the Sahara, from the Atlantic to the Euphrates.

As the scion of a provincial family, his claim to the imperial throne was not clear and only a last-minute adoption by Trajan, plus endorsement by the army, secured the succession.

He had to assert his legitimacy as ruler, which he did with military rigour. He cajoled the common masses by remitting tax payments. His coinage proclaimed a new-found stability of the economy and praised him as the restorer and enricher of the Roman empire. He was clearly a master of public relations.

No one can fail to note the sheer energy and willpower that drove him. He was intellectually and artistically curious, yet a passionate hunter and soldier. He was passionate about architecture, initiating a massive building programme throughout the empire.

The Historia Augusta, drawing on lost sources, described him as "in the same person, austere and genial… deceitful and straightforward, cruel and merciful… in all things changeable". So what do we in the 21st century make of him?

Exhibition curator Thorsten Opper has been fortunate in his friends. Preparing for the show he achieved most of his wished-for long list. Eleven nations loaned artefacts, though there are none, alas, predictably, from Greece.

The most spectacular are a colossal marble head, leg and foot, found only a year ago in Turkey at the city site of Sagalasoss. They are cleverly lit and form the spectacularly theatrical introduction to the exhibition. It is a pity that the head was not elevated to the original five-metre height of the statue so that we might have experienced its intimidatory grandeur.

Under the dome of the Reading Room, itself inspired by Hadrian's Pantheon, a series of displays illustrate Hadrian's genealogy. Detailed models of his villa and classical statuary from all over the empire indicate the opulence of his lifestyle. His relationships with his wife Sabina and with his young lover Antinous are carefully delineated.

The ethos of a gay relationship in Graeco-Roman times differs markedly from today. What shocked the contemporaries of Hadrian was not the openly displayed bond between man and boy, but the seemingly excessive grief after the drowning of Antinous and his subsequent deification.

The eroticism of the many statues of the boy, notably the one on loan from the Vatican where he appears in the guise of Osiris, is extraordinary.

Hadrian's military excursions are lucidly explained, including the putting down of two Jewish revolts. I stood in front of preserved domestic artefacts from the Cave of Letters west of the Dead Sea, relics of the followers of Simon Bar Kokhba and Rabbi Akiba.

Beside me stood an elderly Jew who said his prayers and then quietly cursed Hadrian as worse than Hitler. Clearly the legacy of Hadrian is still vibrant and varied.

I would advise all but serious classicists to read the excellent guide book before visiting, to take advantage of the series of lectures or view the short downloadable videos on the museum's website. Though the labelling is clear and the language exemplary, the exhibition is cerebrally demanding, but very worthwhile.

What distinguishes this unprecedented coming together of so many artefacts is that they do in a very real sense talk to each other and to us. Present experiences can indeed give us a better understanding of the past.

Peter Lewis is a writer and a past director of Beamish, the North of England Open Air Museum