> The use of the word "libertarian" to describe a set of political positions can be tracked to the French cognate, libertaire, which was coined in 1857 by French anarchist Joseph Déjacque who used the term to distinguish his libertarian communist approach from the mutualism advocated by Pierre-Joseph Proudhon.[26] Hence libertarian has been used by some as a synonym for anarchism since the 1890s

http://en.wikipedia.org/wiki/Libertarianism#Etymology