Civilisations built on sand

When I say that the British Museum has been brave in mounting its new exhibition, Sudan: Ancient Treasures I hope it will be understood that I'm using "brave" in its diluted form. Though I'm sure archaeology in this region has its problems, we're not really talking Médecins sans Frontières here. And, in any case, "brave" generally needs to be taken with a pinch of salt when it's applied to artistic endeavours. Those who described the National's staging of David Hare's Stuff Happens as "brave" should perhaps have paused for a moment to think about how much nerve would have been required to put on a play which argued that the Prime Minister was right to go into Iraq.

Artists, like politicians, have their constituencies - and it takes courage to alienate them rather than feed their preconceptions. For the most part, though, what "brave" usually means when the arts are concerned is "admirable from my perspective" It's something of that sense that I have in mind when thinking about the British Museum show, because it attempts to do two tricky things.

The first is to mount a show which resolutely goes against the grain of our contemporary taste for the spectacular and the accessible. Sudan: Ancient Treasures does eventually deliver on its title - but you need to have a generous understanding of the word "treasures". True there is some Kushite jewellery and other goldwork -- but such conventionally treasurable objects are vastly outnumbered by far more humble items, gilded only by their rarity or their importance to scholars. One case contains a dead gerbil, for example, found in a storage pit - and included in the exhibition, I guess, because a small-boy fascination with relicts is a sizeable component in the psychological make-up of archaeologists.

Other cases contain quantities of broken pottery and even roughly-shaped stones from the area's Palaeolithic period. One of these is described in the catalogue as "an exceptional object", but it is unlikely to strike anyone but an expert that way, since no-one but an expert could easily distinguish it from the rocks among which it presumably once sat.

The point about all these exhibits is not that they are dull, but that much of their excitement is not on the surface. They need to be steeped in your imagination for a while before they release their flavour - and in our age of instant hit and virtual dazzle that's unusual.

The second thing that the Sudan show tries to do is to overcome a prejudice. This ambition has been hijacked by current affairs. Initially the idea was to underline the overlooked cultural significance of Sudan, but when Darfur hit the headlines the hearts-and-minds mission inevitably became a little more generalised. The museum had to decide how it should proceed and concluded that now, more than ever, the region could do with a bit of positive attention. So instead of charging an admission fee the exhibition would be free and visitors would be encouraged to make a donation to Oxfam or Save the Children - a practical gesture to set alongside the show's implicit argument that atrocity and war is a temporary phenomenon and that civilisation have deep roots here.

This is much easier said than done, though. The very first text panel you see, for example, insists on the area's importance as a cultural fault line. "For millennia Sudan has been the zone of contact between the peoples of Central Africa and those originating from the Mediterranean world" it reads - a line which aims to summon images of fruitful social interchange and trade, but which in the present circumstances can't help but conjure a picture of janjaweed militia ethnically cleansing black Sudanese. It's a zone of contact still, and the contact is violent. What's more, because the exhibition covers such a long time (from prehistoric Sudan to the 19th century) it compresses history in such a way that conflict appears inherent to the area. This is almost certainly a trick of perspective, but, even so, it means that the chief impression left by the exhibition is of Sudan as a geographical palimpsest - washed over by successive civilisations, many of them violently disposed to their predecessors.

So an exhibition intended to counterpoise the region's reputation for intractable strife and civic fragility unfortunately ends up confirming it. It is, as a result, a rather moving exhibition - one that speaks of cultures sophisticated enough to produce objects of durable beauty, but never quite sophisticated enough to endure themselves in an essentially hostile landscape.