Babylon (mod. Hillah), an ancient city on the left bank of the Euphrates, about 70 m. S. of Bagdad. "Babylon" is the Greek form of Babel or Bab-ili, "the gate of the god" (sometimes incorrectly written "of the gods"), which again is the Semitic translation of the original Sumerian name Ka-dimirra. The god was probably Merodach or Marduk (q.v.), the divine patron of the city. In an inscription of the Kassite conqueror Gaddas the name appears as Ba-ba-lam, as if from the Assyrian babalu, "to bring"; another foreign Volksetymologie is found in Genesis xi. 9, from balbal, "to confound." A second name of the city, which perhaps originally denoted a separate village or quarter, was Su-anna, and in later inscriptions it is often represented ideographically by E-ki, the pronunciation and meaning of which are uncertain. One of its oldest names, however, was Din-tir, of which the poets were especially fond; Din-tir signifies in Sumerian "the life of the forest," though a native lexicon translates it "seat of life." Uru-azagga, "the holy city," was also a title sometimes applied to Babylon as to other cities in Babylonia. Ka-dimirra, the Semitic Bab-ili, probably denoted at first E-Saggila, "the house of the lofty head," the temple dedicated to Bel-Merodach, along with its immediate surroundings.

Like the other great sanctuaries of Babylonia the temple had been founded in pre-Semitic times, and the future Babylon grew up around it. Since Merodach was the son of Ea, the culture god of Eridu near Ur on the Persian Gulf, it is possible that Babylon was a colony of Eridu. Adjoining Babylon was a town called Borsippa (q.v.).

The earliest mention of Babylon is in a dated tablet of the reign of Sargon of Akkad (3800 B.C.), who is stated to have built sanctuaries there to Anunit and Aē (or Ea), and H. Winckler may be right in restoring a mutilated passage in the annals of this king so as to make it mean that Babylon owed its name to Sargon, who made it the capital of his empire. If so, it fell back afterwards into the position of a mere provincial town and remained so for centuries, until it became the capital of "the first dynasty of Babylon" and then of Khammurabi's empire (2250 B.C.). From this time onward it continued to be the capital of Babylonia and the holy city of western Asia. The claim to supremacy in Asia, however real in fact, was not admitted de jure until the claimant had "taken the hands" of Bel-Merodach at Babylon, and thereby been accepted as his adopted son and the inheritor of the old Babylonian empire. It was this which made Tiglath-pileser III. and other Assyrian kings so anxious to possess themselves of Babylon and so to legitimize their power.

Sennacherib alone seems to have failed in securing the support of the Babylonian priesthood; at all events he never underwent the ceremony, and Babylonia throughout his reign was in a constant state of revolt which was finally suppressed only by the complete destruction of the capital. In 689 B.C. its walls, temples and palaces were razed to the ground and the rubbish thrown into the Arakhtu, the canal which bordered the earlier Babylon on the south. The act shocked the religious conscience of western Asia; the subsequent murder of Sennacherib was held to be an expiation of it, and his successor Esar-haddon hastened to rebuild the old city, to receive there his crown, and make it his residence during part of the year. On his death Babylonia was left to his elder son Samas-sum-yukin, who eventually headed a revolt against his brother Assur-bani-pal of Assyria. Once more Babylon was besieged by the Assyrians and starved into surrender. Assur-bani-pal purified the city and celebrated a "service of reconciliation," but did not venture to "take the hands" of Bel. In the subsequent overthrow of the Assyrian empire the Babylonians saw another example of divine vengeance.

With the recovery of Babylonian independence under Nabopolassar a new era of architectural activity set in, and his son Nebuchadrezzar made Babylon one of the wonders of the ancient world. It surrendered without a struggle to Cyrus, but two sieges in the reign of Darius Hystaspis, and one in the reign of Xerxes, brought about the destruction of the defences, while the monotheistic rule of Persia allowed the temples to fall into decay. Indeed part of the temple of E-Saggila, which like other ancient temples served as a fortress, was intentionally pulled down by Xerxes after his capture of the city. Alexander was murdered in the palace of Nebuchadrezzar, which must therefore have been still standing, and cuneiform texts show that, even under the Seleucids, E-Saggila was not wholly a ruin. The foundation of Seleucia in its neighbourhood, however, drew away the population of the old city and hastened its material decay. A tablet dated 275 B.C. states that on the 12th of Nisan the inhabitants of Babylon were transported to the new town, where a palace was built as well as a temple to which the ancient name of E-Saggila was given.

With this event the history of Babylon comes practically to an end, though more than a century later we find sacrifices being still performed in its old sanctuary.

Our knowledge of its topography is derived from the classical writers, the inscriptions of Nebuchadrezzar, and the excavations of the Deutsche Orientgesellschaft, which were begun in 1899. The topography is necessarily that of the Babylon of Nebuchadrezzar; the older Babylon which was destroyed by Sennacherib having left few, if any, traces behind. Most of the existing remains lie on the E. bank of the Euphrates, the principal being three vast mounds, the Babil to the north, the Qasr or "Palace" (also known as the Mujelliba) in the centre, and the Ishān ‛Amran ibn ‛Ali, with the outlying spur of the Jumjuma, to the south. Eastward of these come the Ishān el-Aswad or "Black Mound" and three lines of rampart, one of which encloses the Babil mound on the N. and E. sides, while a third forms a triangle with the S.E. angle of the other two. W. of the Euphrates are other ramparts and the remains of the ancient Borsippa.