Nabonassar (also
Nabonasser,
Nebo-adon-Assur or
Nabo-n-assar) was a king of
Assyria who founded the
Chaldean and
Babylonian kingdom. He became a king on the
Wednesday of
February 26,
747 BC. At this day the
Nabonassar era (AN - Anno Nabonassari) began, which was used by the Babylonian astronomers and by
Ptolemy. Ptolemy formulated this era in the
proleptic Julian calendar just for his astronomical observations and calculations and it was never used by the Babylonians themselves. Nabonassar ruled until
732 BC[?].