Crass were an English punk rock band formed in 1977 which promoted anarchism as a political ideology, a way of life and a resistance movement. Crass popularised the anarcho-punk movement of the punk subculture, advocating direct action, animal rights and environmentalism. The band used and advocated a DIY punk ethic approach to its sound collages, leaflets, albums and films.

Crass spray-painted stencilled graffiti messages in the London Underground system and on advertising billboards, coordinated squats and organised political action. The band expressed its ideals by dressing in black, military-surplus-style clothing and using a stage backdrop amalgamating icons of perceived authority such as the Christian cross, the swastika, the Union Jack and the Ouroboros.