Monaco is governed under the constitution of 1962. The heredity monarch is the head of state. The minister of state, selected by the monarch from three candidates nominated by France, is the head of goverment. The unicameral legislature is the National Council, which is elected by universal suffrage every five years. The monarch may initiate legislation, but all laws must be approved by the National Council.
By a treaty of 1918, the succession to the throne must be approved by the French government. A law had long stipulated that should the throne become vacant for any reason, including the death of a Grimaldi ruler without a direct blood heir, Monaco would become an autonomous state under French protection. In 2002 the constitution was amended so that any sibling of a ruler who died without issue could inherit the throne.