The Neo-Elamite period is dated from c. 1000 BC until the conquest of Babylonia in 539 BC by Cyrus the Great. For simplicity we have divided it into three phases. While the earliest phase (Neo-Elamite I, c. 1000–744 BC) is poorly known, the middle phase (Neo-Elamite II, 743–646 BC) is amply documented in Assyrian sources, for it was a period of intense conflict between the Assyrian kings and a series of Elamite rulers, often allied with insurrectionists in southern Babylonia. The inscriptions of Shutruk-Nahhunte II (c. 717–699 BC) from Susa reveal continuities with earlier periods in Elamite history, but much of the contemporary archaeological material from the site is badly disturbed. Similarly, it is impossible to correlate much of the military history of Assyria's aggression with Elamite archaeology for the simple reason that many of the towns in western Khuzistan which must have borne the brunt of Assyrian aggression have yet to be identified on the ground, let alone excavated. It is also likely that, under intense Assyrian pressure, Elam as it had existed in the Middle Elamite period was no longer a unified state linking the highlands of Fars and the lowlands of Khuzistan, and that individual cities, such as Hidalu or Madaktu, were no longer bound by the authority of a single Elamite king at any one time.