support of a particular monarch as head of state for a particular territory

Royalism is the political ideology that supports a specific monarch (king, queen, or pretender) as head of state for a country. Royalism is not to the same as monarchism, which supports a monarchical system of government, but not always a specific monarch. For example, in 19th-century France, a royalist might be either a Legitimist, Bonapartist, or an Orléanist.