Gerald Holtom, the designer and a former WWII conscientious objector from London, considered using a Christian cross motif but, instead, settled on using letters from the semaphore alphabet, superimposing N(uclear) on D(isarmament) and placing them within a circle symbolising Earth. The sign was quickly adopted by CND.

How the sign migrated to the US is explained in various ways. Some say it was brought back from the Aldermaston protest by civil rights activist Bayard Rustin, a black pacifist who had studied Gandhi's techniques of non-violence.

American pacifist Ken Kolsbun said: "The sign really got going over here during the 1960s and 70s, when it became associated with anti-Vietnam protests."

As the sign became a badge of the hippie movement of the late 1960s, the hippies' critics scornfully compared it to a chicken footprint, and drew parallels with the runic letter indicating death.

In the 1980s it became the banner of the international grassroots anti-nuclear movemen