The fall of Assur, occurred when the first city and old capital of the Neo-Assyrian Empire fell to Median, Babylonian, and other rebellion-led forces.
The city remained occupied by Assyrians until the massacres of Tamurlane in the 14th century AD.
Ever since the end of Ashurbanipal's reign in 627 BC, the Neo-Assyrian Empire was in an exposed and critical position; civil war, revolts in Babylonia, Anatolia, Caucasus and in the Levant coupled with Median, Babylonian and Scythian invasions proved too much for the empire torn by civil war.
In 616 BC, the Babylonians established their de facto independence from the Assyrians.
Finally, after bloody hand-to-hand clashes (many skulls and skeletons were later found), the city was taken in 614 BC.