The Collaborative International Dictionary of English v.0.48:

Ultramontanism \Ul`tra*mon"ta*nism\, n. [Cf. F.
   ultramontanisme.]
   The principles of those within the Roman Catholic Church who
   maintain extreme views favoring the pope's supremacy; -- so
   used by those living north of the Alps in reference to the
   Italians; -- rarely used in an opposite sense, as referring
   to the views of those living north of the Alps and opposed to
   the papal claims. Cf. Gallicanism.
   [1913 Webster]

WordNet (r) 3.0 (2006):

ultramontanism
    n 1: (Roman Catholic Church) the policy that the absolute
         authority of the church should be vested in the pope