 The latter was a vassal of the Assyrian king Shalmaneser IV (783–773 BCE), who was otherwise occupied quelling a civil war in Assyria at the time.This was to set a precedent for all future Chaldean aspirations on Babylon during the Neo Assyrian Empire; always too weak to confront a strong Assyria alone and directly, the Chaldeans awaited periods when Assyrian kings were distracted elsewhere in their vast empire, or engaged in internal conflicts, then, in alliance with other powers stronger than themselves (usually Elam), they made a bid for control over Babylonia.Shalmaneser IV attacked and defeated Marduk-apla-user, retaking northern Babylonia and forcing on him a border treaty in Assyria's favour.