Babylon spent centuries as an unremarkable Sumero-Akkadian town on the Euphrates. Late in the 19th century BCE it passed under an Amorite dynasty, and under Hammurabi (c. 1792–1750 BCE) it became the dominant political power in Mesopotamia.

Hammurabi began with a small kingdom. Through careful alliance diplomacy and targeted campaigns he subdued Mari, Eshnunna, and Larsa within a few decades, unifying southern Mesopotamia. His law collection is treated in its own entry; but Babylon's significance reaches well beyond a single code.

For the next two millennia, the city remained the symbol of Mesopotamian civilization. Literature, astronomy, mathematics, and ritual were anchored here. In the 6th century BCE, after the fall of Assyria, Babylon would rise again under Nebuchadnezzar II — celebrated for the Ishtar Gate and the legendary Hanging Gardens. More than a city, Babylon was an idea: a stand-in for the centre of empire, law, and knowledge in the ancient imagination.