King Ahsheri's successor, Ualli, as an ally of Assyria, took the side of the Assyrians against the Iranian Medes ("Madai"), who were at this point still based to the east along the southwest shore of the Caspian Sea and revolting against Assyrian domination. The Medes and Persians were subjugated by Assyria. However, the Neo-Assyrian Empire, which had dominated the region for three hundred years, began to unravel, consumed by civil war after the death of Ashurbanipal in 627 BCE. The upheavals in Assyria allowed the Medes to free themselves from Assyrian vassalage and make themselves the major power in ancient Iran at the expense of the Persians, Mannaeans and the remnants of the indigenous Elamites whose kingdom had been destroyed by the Assyrians. At the battle of Qablin in ca. 616 BCE the Assyrian and Mannaean forces were defeated by Nabopolassar's troops. This defeat laid open the frontiers of the Land of the Manneans which fell under the control of Media between 615 BCE and 611 BCE.