Nebuchadnezzar III, also known as Nidintu-Bêl or Naditabaira, was a Babylonian rebel in late 522 BC during the reign of Darius I. The earliest extant document mentioning him as King is dated to the 3rd of October 522 BC with his death dated on the 18th of December 522 BC.
Darius I asserted that Nidintu-Bel lied by 1. simply claiming to be king and 2. by claiming that he was a son of the last official king of Babylon, Nabonidus when he was really the son of a man named Kîn-Zêr[1].
His story is memorably etched into the side of a mountain in the famous billboard sized Behistun Inscription. Therein we learn that on 13th of December, Nidintu-Bel was swiftly defeated by Darius first in a battle at the Tigris[2] and then on the 18th of December at a city called Zâzâna, on the Euphrates as one marches toward Babylon[3]. Nidintu-Bel then fled into Babylon, after which Darius I took the city before capturing and executing Nidintu-Bel therein[4].