It took him nigh on 2,000 years, but the Roman emperor Hadrian has finally returned to inspect his greatest legacy - the wall he built to consolidate the borders of his empire and control the troublesome Scots.

In a symbolic act with political resonance, a priceless bronze head of Hadrian was installed this week in the Tyneside town of Wallsend; or, as Hadrian would have put it, from Londinium to Segedunum - the Roman name for Wallsend.

The head is one of only three of Hadrian in the world. It was recovered from the Thames, where it had been preserved by silt since Roman times.

Hadrian's head was accompanied on the journey by Neil MacGregor, the director the British Museum. He said: “This is a great moment - to reunite Hadrian with his wall. I thought it was profoundly moving to see him there.”

The emperor is believed to have travelled North in AD122 to oversee the design of his great strategic edifice, a 73-mile barrier stretching across the country. But he never came back after its completion in about AD126.

His bronze head is the star of an exhibition called The Face of An Emperor: Hadrian Inspects the Wall. In June the head returns to London for the British Museum's summer exhibition, Hadrian: Empire and Conflict, which explores the modern political significance of a ruler who stabilised over-stretched boundaries and coped with intractable problems in Palestine, and whose first act was to withdraw his troops from Iraq.

That he also had to cope with obstinate Scots and nascent Scottish nationalism, 2,000 years before Gordon Brown faced Alex Salmond, makes the modern parallels compelling.

It must have been a shock for Hadrian, a warm-blooded Spaniard who was not only gay but loved architecture and art, to reach a corner of his Empire that was cold, grim and troubled by barbarians from the far north and by ungrateful Brittunculi, the “wretched little Britons”.

Ralph Jackson, the curator of Romano-British collections at the British Museum, said that Hadrian came to Britain intent on sorting out difficulties. He wanted to encourage the building of towns and end the fighting on the frontiers.

“He came north and it's quite possible, because of his interest in so many things, including architecture, that the original blueprint for the wall was his. You can see his imprint in the first stages of the wall.”

Mr Jackson said it was “a pleasing conceit” to bring Hadrian's head - 1 times lifesize - back to his wall.

The discovery of the bronze head in 1834 was an extraordinary stroke of luck. The old London Bridge, with 20 arches, had been demolished three years earlier and the Thames was being dredged before the new one, with five arches, was built. The head just popped up from the river bed on the Southwark side, where it had lain for 1,500 years. Apart from two holes, it was in remarkably good condition.

Mr Jackson has a theory about how the head came to be in the water. He believes it came from a full statue of Hadrian that was either brought to London for the occasion of his three-month stay in AD122, or created in Britain for his visit. After Hadrian's reign ended in AD138, Mr Jackson believes, the statue was toppled and the body melted down but someone saved the head, which was ritually placed in the river.

Mr Jackson said: “Evidence supports that. There is the cult of the head and the importance of water in ritual activities, plus the fact that the head is very heavy and would have had to be carried from where the statue stood, which would have been at the Basilica, in Cornhill in what is now the City of London.

“The other factor is that it was placed in the middle of the river, not dumped at the side.”

Thorsten Opper, the curator of the forthcoming Hadrian exhibition at the British Museum, said: “What we forget is that the wall was a very efficient and brutal tool of oppression. Now we think of it as a world heritage site, but for those who lived here, it must have been awful if their family was split and some lived on the other side of the wall.

“One can make comparisons in today's society, for instance, with the wall built by the Israelis on the West Bank.”

A wall that was built to last

73

miles long

4

years to build AD122-126

16

forts along its length

1million cubic metres of stone

15

feet high

10

feet thick

10,000 auxiliary troops were raised from other

parts of the empire

to man it

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