When the President of the United States says that he’ll be designating Antifa as a terrorist organization, a part of me thinks: well go on then, let’s see you try. Because this awful, foreign-sounding word “antifa” is only an abbreviation of “anti-fascist.” Organizations can be banned, but it isn’t so easy to do the same with ideas.

I’m a historian, and I’ve been writing about anti-fascism for twenty-five years. The first activists I interviewed were a generation of Jews who in 1946 and 1947 were shocked to see people marching through the streets of London wearing black shirts and swastikas and armed for a fight. This was Britain, not America, so the fascists’ weapons were iron knuckledusters, or potatoes with razors sticking out from them.

Probably the best-known former member of the Group was the hairstylist Vidal Sassoon. In Vidal: The Autobiography he describes working from a hairdressing salon next to Harrods during the week, while fighting fascism at his weekends.