Monarchy originally meant ‘the rule of one’, but the word has now come to be attached to the constitution of kingship (and queenship) that is usually conceived as hereditary, though many posts which we would consider as monarchs (Roman emperors, Holy Roman Emperors, and kings of Poland, for example) were, at least nominally, non‐hereditary.
Monarchism is generally a belief in the necessity or desirability of monarchy. An extreme version of this would be to believe in a monarch who actually ruled and did not merely reign, who had an absolute, perhaps divinely ordained, right to do so, and who acquired this right by heredity. But all of these beliefs are very difficult to sustain in the early twenty‐first century. Contemporary monarchists normally support a ‘limited’ monarchy, and ground their support in the general utility of the institution in a particular context. For example, they may believe it is best to have a head of state who is ‘above’ politics and does not have to compete for the role. Or they may believe in the ruling family as a symbolic embodiment of a country's history. Monarchy is often seen as a ‘dignified element’, in Bagehot's phrase, which legitimizes the authority of the state without the need for precise constitutions and justifying principles which would prove divisive. It was largely on these negative grounds that the Australian electorate chose to retain the services of a monarch who lived more than ten thousand miles away in a referendum in 1999.