The Code of Ur-Nammu, attributed to the king of the Third Dynasty of Ur or his son Shulgi, is the oldest surviving law code, written in Sumerian on clay tablets some three centuries before Hammurabi. It opens with a prologue asserting royal authority and a duty to protect the weak, then sets out case law in a conditional 'if … then' form, fixing fines in silver for many offences rather than imposing physical retaliation. It governed a centralised state that administered cities, canals and granaries through a literate bureaucracy. Several provisions concern property, boundaries and the obligations attaching to land.
It marks the beginning of codified, state-administered law as an instrument of urban government, establishing the principle that rulers issue and publicise written rules binding on the governed.