The organization was founded in 1961 as The Norwegian Student's and Pupil's Language Association (NSEM) and initially operated as independent from Noregs Mållag.
There have been disagreements on how and why awareness of the cause should be spread, and in how the community should place itself on issues not immediate to the cause – for instance in the case of Norwegian-EU relations – and turbulence within NSEM/NMU has occationally led to a relationship that is directly hostile.
The organization's initial name reflect its organizational structure during the 1960's and 70's, when NMU operated largely through local student and pupil associations at high schools, colleges and universities.
This is parallel to the struggle of Noregs Mållag in uniting the individual associations into a national one, which was also difficult due to historic resistance to centralism that local communities often had inherent to them.
The national camp came out on top, however through a semantic compromise in the charter: "NMU shall strive towards a liberation of the language for all norwegians, in speech and in writing".