<P> Nowadays a parliamentary democracy that is a constitutional monarchy is considered to differ from one that is a republic only in detail rather than in substance . In both cases, the titular head of state--monarch or president--serves the traditional role of embodying and representing the nation, while the government is carried on by a cabinet composed predominantly of elected Members of Parliament . </P> <P> However, three important factors distinguish monarchies such as the United Kingdom from systems where greater power might otherwise rest with Parliament . These are: the Royal Prerogative under which the monarch may exercise power under certain very limited circumstances; Sovereign Immunity under which the monarch may do no wrong under the law because the responsible government is instead deemed accountable; and the monarch may not be subject to the same taxation or property use restrictions as most citizens . Other privileges may be nominal or ceremonial (e.g., where the executive, judiciary, police or armed forces act on the authority of or owe allegiance to the Crown). </P> <P> Today slightly more than a quarter of constitutional monarchies are Western European countries, including the United Kingdom, Spain, the Netherlands, Belgium, Norway, Denmark, Luxembourg, Monaco, Liechtenstein and Sweden . However, the two most populous constitutional monarchies in the world are in Asia: Japan and Thailand . In these countries the prime minister holds the day - to - day powers of governance, while the monarch retains residual (but not always insignificant) powers . The powers of the monarch differ between countries . In Denmark and in Belgium, for example, the Monarch formally appoints a representative to preside over the creation of a coalition government following a parliamentary election, while in Norway the King chairs special meetings of the cabinet . </P> <P> In nearly all cases, the monarch is still the nominal chief executive, but is bound by convention to act on the advice of the Cabinet . Only a few monarchies (most notably Japan and Sweden) have amended their constitutions so that the monarch is no longer even the nominal chief executive . </P>

The declaration of independence was the first legal document to limit the power of a monarchy