Historical Basis
“In the first year of Neriglissar (king of Babylon), only two years after the death of Nebuchadnezzar, broke out that fatal war between the Babylonians and the Medes, which was to result in the utter subversion of the Babylonian kingdom.”
“Cyaxares, king of the Medes, who is called “Darius” in Daniel 5:31, summoned to his aid his nephew, Cyrus, of the Persian line, in his efforts against the Babylonians.”