He founded what was afterwards known as the Persian empire.
The overthrow of the Medes gave Cyrus control over Assyria, and it was to be expected that his gaze should be turned in the direction of Babylonia.

Nabonnedos recognized the danger, but all his efforts to strengthen the powers of resistance to the Persian arms were of no avail.

Civil disturbances divided the Babylonians.

The cohesion between the various districts was loosened, and within the city of Babylon itself, a party arose antagonistic to Nabonnedos, who in their short-sightedness hailed the advance of Cyrus.

Under these circumstances, Babylon fell an easy prey to the Persian conqueror.