The ultimate authority in a state is

The ultimate authority in a state is sovereignty. Sovereignty is the supreme power and authority of a state over its people and territory. It is the foundation of the modern state system and represents the highest form of political power. Sovereignty encompasses the right to make laws, levy taxes, maintain order and security, and defend against external threats. Sovereignty is an important concept because it establishes the legitimacy of the state and its political institutions. Legitimate authority is the right to exercise power and control over a given territory and its people. The legitimacy of the state derives from the recognition and acceptance of its authority by its citizens and other states in the international system. Therefore, the ultimate authority in a state is sovereignty, which confers the power and legitimacy necessary for the state to exercise its authority over its people and territory.