As it happens, the Elamites managed to stay independent for some time after this disaster. The devastation was less complete than Assurbanipal boasted, and Elamite rule, though rather broken up, continued until 540 BC, when Achaemenid rule begins in Susa. Under the Parthian period, a kingdom of Elymais existed which survived until its extinction by Sassanid invasion in the early third century AD. It was in the heartland of ancient Elam.