What is "gallicanism"

Gallicanism \Gal"li*can*ism\, n. The principles, tendencies, or action of those, within the Roman Catholic Church in France, who (esp. in 1682) sought to restrict the papal authority in that country and increase the power of the national church.
--Schaff-Herzog Encyc.

Gallicanism is the belief that popular civil authority—often represented by the monarchs' authority or the State's authority—over the Catholic Church is comparable to that of the Pope's. Gallicanism is a rejection of ultramontanism; it is akin to a form of Anglicanism but is nuanced, however, in that it plays down the authority of the Pope in Church without denying that there are some authoritative elements to the office associated with being primus inter pares ( first among equals). Other terms for the same or similar doctrines include Erastianism, Febronianism and Josephinism.

University of Notre Dame professor John McGreevy defines it as "the notion that national customs might trump Roman (Catholic Church) regulations."

The doctrine originated in France (the term derives from " Gaul"). In the 18th century it spread to the Low Countries, especially the Netherlands, as well. It is unrelated to the first-millennium Catholic Gallican rite.