Late in April 2004, there was a tense gathering in a bank vault beneath the Presidential Palace at Kabul. This was the moment when it would finally be discovered whether the greatest archaeological treasures of ancient Afghanistan had survived over two decades of anarchy, civil war, looting and deliberate iconoclastic destruction. Present, in addition to a scrum of diplomats, press and officials were the director of the Kabul Museum, the Minister of Culture and the Russian archaeologist who had found many of the most remarkable of these objects.

With difficulty the first heavy safe was opened, and within were seen piles of plastic bags with old labels attached. The first was unwrapped. The Russian archaeologist Viktor Sarianidi, then in his seventies, examined several items. Then he smiled. On one piece he recognised a repair he himself had made a quarter of a century before. Rumours had circulated, suggesting that these things had been stolen, sold on the black market, the gold melted down. Here was absolute proof they were intact.

Indeed, astonishingly, and against all odds, these marvellously beautiful and evocative works of art were still in excellent condition. Some of the most spectacular will go on show next week at the British Museum in Afghanistan: Crossroads of the Ancient World....