After the death of Assurbanipal in 631 BC, the Neo-Assyrian Empire entered a period of instability.
This was the moment when the Babylonian ruler, Nabopolassar, led a revolt against Assyrian rule.
The situation became highly dangerous for Assyria with the offensive of Cyaxares, king of the Medes, in 616 BC.
The Median forces swiftly conquered Tarbisu and decisively defeated the Assyrian army at the Battle of Assur.
Then, they joined the Babylonian army and launched a combined offensive against Nineveh in 612 BC.