The Code of Ur-Nammu is the oldest surviving written legal compilation. It was issued under King Ur-Nammu (or possibly his son Shulgi) during Mesopotamia's Third Dynasty of Ur (Neo-Sumerian period), recorded in cuneiform on clay tablets.

The code opens with a short prologue: the king declares his duty to protect the orphan from the rich man and the widow from the powerful. What follows are casuistic statutes — "if X, then Y" — covering injuries, property, marriage, and slavery. Unlike Hammurabi's later "eye for an eye" principle, Ur-Nammu's code largely substitutes monetary compensation for physical retribution: an injury is settled with a payment in silver.

The Code of Lipit-Ishtar, compiled roughly 150 years later by a king of Isin, continues the same tradition. These texts are the earliest written evidence that law could be conceived as a body of declared rules issued by royal authority — that judgement should follow stated norms rather than ruler's whim.