Cyrus Takes Babylon (539 BCE)

In October 539 BCE Cyrus the Great defeated the Babylonian army at Opis on the Tigris, his troops entered Babylon without a battle on about 12 October, and Cyrus himself rode into the city on about 29 October. The fall of Babylon ended the last great Mesopotamian empire and gave Persia Mesopotamia, Syria and the Levant, making it the largest state the world had yet seen.

Babylon under Nabonidus

Babylon in 539 BCE was the heart of an empire that had destroyed Assyria and Jerusalem two generations earlier. Its king, Nabonidus, was an outsider: he was not from the royal family of Nebuchadnezzar, and he was deeply devoted to Sin, the moon god of Harran, his mother’s city.

For about ten years, roughly 552 to 543 BCE, Nabonidus lived at the oasis of Tayma in Arabia, leaving his son Belshazzar (Bel-sharra-usur) to govern Babylon. The Nabonidus Chronicle notes year after year that the king did not come to Babylon, so the New Year festival of Marduk, which needed the king, was not properly held. After the conquest, Babylonian priests wrote bitterly against him. The text known as the Verse Account of Nabonidus mocks him as a madman who neglected Marduk.

Those hostile writings were composed under Persian rule, and modern historians such as Paul-Alain Beaulieu treat them with care. Nabonidus was an active builder and a serious, if unusual, king. Still, his religious choices and long absence seem to have cost him support among the powerful temple elite of Babylon.

The Battle of Opis

By 539 BCE Cyrus controlled Iran, Media and Anatolia, and Babylon was surrounded on two sides. As the danger grew, Nabonidus brought the statues of gods from other Babylonian cities into the capital, apparently for safety. The Chronicle says the gods of Marad, Kish and other towns entered Babylon that year.

Cyrus advanced down the Tigris. In the month of Tashritu, the Chronicle says, he fought the army of Akkad (Babylonia) at Opis, on the Tigris near the point where it comes closest to the Euphrates. The Babylonians retreated, and Cyrus carried off plunder and killed people. This short line is important: the conquest of Babylonia began with a real and bloody battle, something the later Cyrus Cylinder leaves out entirely.

The entry into Babylon

After Opis, resistance collapsed with remarkable speed. The Chronicle gives the sequence day by day:

1. 14 Tashritu (c. 10 October) Sippar is taken without a battle. Nabonidus flees.
2. 16 Tashritu (c. 12 October) Ugbaru, governor of Gutium, and the army of Cyrus enter Babylon without a battle. Nabonidus, who has returned to the city, is captured.
3. Following weeks Shield-bearing troops guard the gates of Esagila, Marduk’s temple, and the temple rites continue without interruption.
4. 3 Arahsamnu (c. 29 October) Cyrus enters Babylon. Green branches are spread before him and peace is imposed on the city.
5. Night of 11 Arahsamnu Ugbaru dies.
6. Kislimu to Addaru (December 539 to March 538) The gods Nabonidus had brought to Babylon are returned to their own cities.

Cyrus’s governor, called Gubaru in the Chronicle, appointed officials in Babylon. Who Ugbaru was is not certain. One common view is that he was a Babylonian provincial governor who had changed sides, which would help explain how easily the city opened its gates. Xenophon’s “Gobryas”, a defecting Assyrian nobleman, may be a distant memory of him.

Herodotus, Daniel and the diverted river

Later stories turned the fall of Babylon into something more dramatic than the Chronicle’s dry record.

Herodotus (1.189–191) says Cyrus first punished the river Gyndes for drowning one of his sacred white horses by dividing it into 360 channels. At Babylon, he says, the Persians diverted the Euphrates into a lake so that the water in the city fell to the height of a man’s thigh, and they walked in along the riverbed. The city was so large that people in the centre were still celebrating a festival when the outskirts had already fallen. Xenophon tells a similar story. No Babylonian source mentions a siege or a diversion of the river, and the Chronicle says the city was entered without a fight.

The Book of Daniel (chapter 5) sets the end of Babylon at a feast of Belshazzar, where a hand writes on the palace wall “mene, mene, tekel, upharsin” and Daniel reads it as the king’s doom. That night, the text says, Belshazzar was killed and “Darius the Mede” took the kingdom. Historians read the chapter as a later religious narrative: Belshazzar is real, but he was never king in his own right, and no “Darius the Mede” appears in any record of the time.

Berossus, a Babylonian priest writing in Greek around 280 BCE, gives a quieter ending. Nabonidus, he says, shut himself up in Borsippa, then surrendered, and Cyrus treated him kindly and sent him to live in Carmania (Kerman) in Iran.

Why Babylon fell so easily

Historians usually point to several causes working together. Opis destroyed Babylon’s field army. Part of the Babylonian elite had reason to be unhappy with Nabonidus and may have negotiated in advance. Cyrus also had a reputation, built in Media and Lydia, for keeping local officials and institutions in place. Business archives from Babylonian families such as the Egibi firm continue almost without a break from the reign of Nabonidus into that of Cyrus, which suggests that ordinary life in the city was barely disrupted.

Pierre Briant describes the conquest as carefully prepared, both militarily and politically. The Persian version, which presents Cyrus as Marduk’s choice welcomed by a grateful people, was written afterwards and is discussed on The Cyrus Cylinder.

After the conquest

Cyrus took the old Mesopotamian titles “king of Babylon, king of the lands”. For part of 538 BCE Babylonian documents name his son Cambyses as king of Babylon, a sign that Cyrus was preparing his succession (see Cambyses II). Babylon stayed one of the empire’s capitals, and its new rulers inherited its western provinces, including Judah, whose exiles’ return is told on Cyrus and the Return of the Jews. How the city fared over the next two centuries is covered on Babylon under Persian Rule.