A "reactionary" is an individual who seeks a return to a previous state (the status quo ante) and by extension any ideology or political or social movement espousing such a viewpoint. The term is meant to stand in opposition to and as one end of a political spectrum whose opposite pole is "progressive". While it has not been generally considered a term of praise it has been adopted as a self-description by some such as H. L. Mencken<1>.
The French Revolution gave the English language two politically descriptive words denoting anti-progressive politics: reactionary and conservative. Reactionary derives from the French word réactionnaire (an early nineteenth-century coinage), and conservative from conservateur, identifying monarchist parliamentarians opposed to the revolution.<2> In this French usage, reactionary denotes "a movement towards the reversal of an existing tendency or state" and a "return to a previous condition of affairs." The Oxford English Dictionary cites the first English-language usage was by John Stuart Mill, in 1840: "The philosophers of the reactionary school—of the school to which Coleridge belongs".<3>
During the French Revolution, conservative forces (especially the Roman Catholic Church) organized opposition to the progressive socio-political and economic changes wrought by the revolution, and to fight to restore the temporal authority of the Church and Crown. In nineteenth-century European politics, the reactionary class included the Roman Catholic Church's hierarchy—the clergy, the aristocracy, royal families, and royalists—believing that national government is the sole domain of the Church and the state. In France, supporters of traditional rule by direct heirs of the House of Bourbon dynasty were labeled the legitimist reaction. In the Third Republic, the monarchists were the reactionary faction, later renamed conservative.<2> In Protestant Christian societies, reactionary described those supporting tradition against modernity.
In the nineteenth century, reactionary denoted people who idealised feudalism and the pre-modern era—before the Industrial Revolution and the French Revolution—when economies were mostly agrarian, a landed aristocracy dominated society, an hereditary king ruled and the Roman Catholic Church was society's moral centre. Those labeled as reactionary favoured the aristocracy instead of the middle class and the working class. Reactionaries opposed democracy and parliamentarism.
http://en.wikipedia.org/wiki/Reactionary