LONDON, Sept. 11 - An early reference to Alexander of Macedon is the first hint of where the British Museum is heading in its new exhibition, "Forgotten Empire: The World of Ancient Persia." After all, to Persians then and Iranians now, there was nothing great about the Alexander who crushed the largest empire the world had yet known. Indeed, his burning of Persepolis in 331 B.C. was considered an act of vandalism. But the show, which runs through Jan. 8, goes further, challenging the version of history that ancient Greece, starting with Herodotus, bequeathed to the West. Put simply, in...