Basic concepts of international law such as treaties can be traced back thousands of years. Early examples of treaties include around 2100 BC an agreement between the rulers of the city-states of Lagash and Umma in Mesopotamia, inscribed on a stone block, setting a prescribed boundary between their two states.

International law, also called public international law or law of nations, the body of legal rules, norms, and standards that apply between sovereign states and other entities that are legally recognized as international actors. The term was coined by the English philosopher Jeremy Bentham (1748–1832).