The name Belshazzar is Babylonian in origin, meaning 'Bel protect the king' or 'Bel, protect his life.' He was the last king of Babylon, son of Nabonidus, who saw the handwriting on the wall and was slain that night.
Belshazzar represents the apex of human arrogance against God. By using the sacred vessels from Solomon's Temple for his drunken feast, he committed sacrilege against the holy things of the Most High. The immediate divine response — the mysterious hand writing Mene, Mene, Tekel, Parsin — declared his kingdom numbered, weighed, and divided (Daniel 5:25-28). Daniel's interpretation fulfilled that very night. No earthly power is exempt from the accounting of the Holy One. Kingdoms rise by His permission; they fall by His decree.