<P> The Fall of Babylon denotes the end of the Neo-Babylonian Empire after it was conquered by the Achaemenid Empire in 539 BCE . </P> <P> Nabonidus (Nabû - na'id, 556--539 BCE), son of the Assyrian priestess Adda - Guppi, came to the throne in 556 BCE, after overthrowing the young king Labashi - Marduk . For long periods he entrusted rule to his son, prince and coregent Belshazzar, who was a capable soldier, but a poor politician . All of this left him somewhat unpopular with many of his subjects, particularly the priesthood and the military class . To the east, the Achaemenid Empire had been growing in strength . In 539 BCE, Cyrus the Great invaded Babylonia, turning it into a colony of Achaemenid Persia . Cyrus then claimed to be the legitimate successor of the ancient Babylonian kings . As it turns out, Cyrus was very popular in Babylon itself, in contrast to Nabonidus . </P>

Who conquered the babylonian empire in 539 bc