Sovereignty

Sovereignty is the quality of having supreme, independent authority over a territory. It can be found in a power to rule and make law that rests on a political fact for which no purely legal explanation can be provided.
The current notion of state sovereignty was laid down in the Treaty of Westphalia (1648), which, in relation to states, codified the basic principles of territorial integrity, border inviolability, and supremacy of the state.

A sovereign is a supreme lawmaking authority.