Defensa Interior (DI) was a militant anarchist organisation, founded in September 1961 by the congress of the Movimiento Libertario Español (Spanish Libertarian Movement). It was disbanded by their 1965 congress.
The aim of DI was to fight the regime of General Francisco Franco.
Defensa Interior was a precursor to later anarchist groups such as the First of May Group, GARI, and the Angry Brigade .
References
Defensa Interior Wikipedia(Text) CC BY-SA