The Harrods of the ancient world

How could something so fragile last so long?

I gazed at the remains of brittle gold bowls and goblets. I could see where the stem of the goblet should be. The amazing thing is not that it has vanished but the thin, ridged bowl should have survived. I peered closer to make out the outlines of bulls on part of a bowl. A craftsman scored them gently into the gold around four thousand years ago. They are evidence of a vanished civilization of which little else is known. They come from Afghanistan.

I was hesitant about visiting the Afghan Treasures exhibition at the British Museum. I thought uncomfortably of conquerors, loot and triumphal processions. Exhibitions often arrive with an agenda, especially when they have been negotiated by diplomats. But this exhibition seems to have a gentler and more laudable cause. The British Museum has been restoring ivories that were stolen in the looting of Kabul Museum and recovered by an unnamed philanthropists. The British Museum staff have been working with the staff of Kabul Museum and the exhibition, however dependent on diplomatic goodwill and corporate sponsors, comes out of their joint work. The exhibition tells another story too – of museum staff who hid the treasures so that the history of their country could be preserved.

The history of Afghanistan is not well known. There is much that has not yet been recovered or understood. Western history books have tended to simplify the region as a place of romantic barbarism which briefly encountered civilization with the arrival of Alexander the Great. Alexander the Great, who married an Afghan wife and adopted local customs, may have viewed it differently.

So far as I can gather and recollect, the region had two reasons for importance in the world. It was a source of lapis lazuli, which was rare and much in demand. And although its terrain is difficult by contemporary vehicles, it stood on major trade routes, bordering India, China and the Persian Empire. Traders went as far as Greece and Rome, although the journey each way would have taken a year. The treasures they brought back, particularly to Begram, are protected in glass cases in the exhibition.

Captions show the uncertainty of the curators about the exhibits on view. There is a head of Silenus, clearly recognizable, but did the Afghans really know who Silenus was? Its unclear whether the owners of valuable items purchased deities or just attractive statues – rather as a modern mantlepiece may bear statues of Ganesh or the Buddha without necessarily demonstrating any religious allegiance or knowledge.

There's glass, too – Roman glass most probably or perhaps made in Egypt - the curators cannot be sure how it reached Begram from Rome since the way was blocked by war with Parthia. One piece is enamelled with full-length figures which even I can see are Roman in style. Another's delicately ornamented with vines made from the glass itself. But beside these are statues carved in turned ivory – chair-legs, the inscription suggests – each with a swaying female figure in what seems to me an Indian style. There are glass fish, a face that resembles a Greek or Chinese theatrical mask. There are Corinthian columns and finials. Some items must have been made in Afghanistan by craftsmen who had learnt skills from crafts practised elsewhere. But many items are imports, suggesting a place like Britain today where beautiful objects from all over the world can be prized and owned.

Half-way round the exhibition, I realised something else that was troubling me, though it's not unusual. I had little sense of the lives of the people who owned these objects, other than that they were very rich and could afford goods imported from far-off places. It was as if, one day far in the future, someone were to excavate Harrods and, finding only a few of the goods on show, tried to understand life today on that basis. Perhaps that is what has survived. Perhaps these expensive, traded goods represent the Harrods of the ancient world.

As I wandered through the exhibition, the past seemed both more distant and more familiar. I couldn't grasp past Afghan cultures but then, if asked, I couldn't give a simple account that took in the whole of west European culture today. Artefacts left by Afghan trading centres, which drew goods and influence from across the world, speak of a complex, varied society. This shouldn't be surprising or unusual. But I began to realise that many exhibitions treat the past as a collection of small, separate societies. They don't just assume that societies are culturally pure – they often treat cultural purity as something good in itself. The textbooks I studied at school were wary of cultural mixing. Rome's interest in things Greek was regarded with disdain although the Renaissance interest in Greek art and sculpture was excused as a means of regaining artistic purity after the confused muddle of the Middle Ages.

Looking at the wide range of objects on display and marvelling at their variety, I realised how much ancient history has been filtered through subjective and questionable value judgements. I suppose curators have to simplify – just as their displays provide the kind of neat, comforting pattern humans are trained to prefer. But in real life I like variety and complexity – and am glad that human existence resists a neatly moral narrative arc.

At last I neared the object I recognized from the posters for the exhibition: the gold crown once worn, so the captions assured me, by a nomad princess. I expected something bright and golden but I hadn't realised the tiny golden discs would tremble continuously, as though there were a breeze or breath inside the glass case. I read that the crown could be packed away and folded – and that all the nomad treasures, buried two thousand years ago, could be carried easily on horseback. In my imagination an Afghan princess rode through wild landscapes, the trembling crown on her head and a gold-studded cloak behind her. It's an improbable fantasy. I have no idea what the concept “princess” means in terms of nomadic people two thousand years ago - I wonder if the women were princesses in any way we can understand.

Little seems to be known of Afghan nomadic life beyond the six graves in Tilya Tepe. But the adornments found in the tombs of five women and one man link the items closely to the humans who wore them. It's not just the photos showing how the bodies lay when the tombs were opened or the glass case where the golden items mark out the shape of a human form. It's more to do with the sense that these items once touched living flesh and the the gold was caught on wisps of cloth the tombs were found. I peered as directed to see that the bracelets show signs of wear – in contact with an arm over time, gold diminishes.

The exhibition isn't big or cheap (I got in for half price – £5 – with my Art Fund membership). Space inside is limited because items are small and, when I visited on Saturday, that meant queuing briefly before reaching most cabinets. I haven't carried away a neat package of knowledge about an obscure culture. Instead I have grounds for wonder and wondering – more than enough.