Forget the glory that was Greece and the grandeur that was Rome. The greatest of all ancient civilisations was, according to a forthcoming show at the British Museum, the Persian empire.
Its achievements have been so overlooked that no exhibition devoted to it has ever been staged. But the empire, which flourished from 550BC until the sacking of Persepolis by Alexander in 330BC, was almost as big as the Roman, stretching "from the Aral Sea to the Persian Gulf, and from the River Indus to Libya", according to the exhibition's curator, John Curtis.
But for the past 2,500 years, it has been the victim of Greek propaganda. Portrayed by classical Athenian writers, especially Herodotus, as despotic, luxurious, effete and cruel, the Persians have been thoroughly vilified.
Some argue that the Greeks' characterisation of their near and Middle Eastern neighbours has stuck so successfully it still informs western stereotypes of the Muslim world.
According to Dr Curtis, the Greek portrayal is far from accurate.
The Persians, for example, showed a notable degree of religious tolerance. "The Persian kings never attempted to to impose their own religion on different parts of the empire - in this respect they were enlightened," he said.
The empire bridged Europe and the great centres of Assyrian and Babylonian learning, he said.
The objects in the exhibition, nearly three years in the planning and many on loan from the Tehran National Museum and the Louvre, bear out his argument. Splendid bronze figures of lions, finely-worked cloisonné jewellery and a lapis lazuli carving of the head of a young man are just some of the objects in the show.
As for the Graeco-Persian wars, Athens' proudest moment, when it defeated King Xerxes and ushered in the golden age, Dr Curtis is dismissive. "As far as the Persians were concerned, they were nothing more than frontier skirmishes."
The World of Ancient Persia is at the British Museum, London WC1, from September 9 until January 8