Daniel 5:30

In that night. Although Belshazzar is not mentioned in the cuneiform sources describing the fall of Babylon, Xenophon declares that “the impious king” of Babylon, whose name is not mentioned in the account, was slain when Cyrus’ army commander Gobryas entered the palace (Cyropaedia vii. 5. 30). Although it must be recognized that Xenophon’s narrative is not historically reliable in all details, many of his statements are based on fact. According to cuneiform sources Nabonidus was absent from Babylon at the time of its capture. When Nabonidus surrendered, Cyrus sent him to distant Camiania. Therefore the king who was slain during the capture of Babylon could have been none other than Belshazzar. For a summary of the history of Belshazzar see Additional Note at the end of this chapter.