The name of the eldest son of the last Neo‐Babylonian king, Nabonidus (556–539 BCE), who for ten years acted as co‐regent during his father's absence in Arabia. Belshazzar (Babylonian Bēl‐sharra‐uṣur, “Bel has protected the kingship”) follows the Aramaic form of the name; elsewhere he is referred to as Balthasar (Bar. 1.11–12) or Baltasar (Josephus), but he should not be confused with the name Belteshazzar applied to Daniel in Babylon (Dan. 1.7).

In his third regnal year, Nabonidus entrusted his army to his eldest son and put under his command troops levied from all lands. The king relinquished all control and entrusted the kingship to Belshazzar while he himself went on a long journey to Tema in the West (Persian Verse Account). Belshazzar, as crown prince and co‐regent, exercised genuine royal powers; he is named in texts dated early in Nabonidus's reign (first, fifth, and seventh years) as controlling his own household and business, and he is associated with Nabonidus in oaths taken by their names in legal transactions in his twelfth‐thirteenth regnal years. He issued an edict outlining a scheme in which land would be managed by specified chief revenue officials. Belshazzar's death at the time of the fall of Babylon to Cyrus in October 539 BCE (Dan. 5.30) is likely, though not mentioned in the Babylonian (Nabonidus) Chronicle, which does refer specifically to the capture but not the death of Nabonidus (he was exiled to Carmania). Attempts to read a broken passage of the Chronicle as telling of Belshazzar's death a month after the Persian entry into Babylon in 539 BCE remain conjectural. There is no extrabiblical confirmation of Belshazzar's feast (Dan. 5).

See Daniel, The Book of

.

Donald J. Wiseman