A generation ago the Achaemenid Empire was a minor sideshow within long-established disciplines. For Greek historians the Persians were the defeated national enemy, a catalyst of change in the aftermath of the fall of Athens or the victim of Alexander. For Egyptologists and Assyriologists they belonged to an era that received scant attention compared with the glory days of the New Kingdom or the Neo-Assyrian Empire. For most archaeologists they were elusive in a material record that lacked a distinctively Achaemenid imprint. Things have changed now. The empire is an object of study in its own...