You might know the symbol above as the “Peace” symbol but it was specifically designed for the Campaign for Nuclear Disarmament in 1958 by designer Gerald Holtom.
Holtom who been a conscientious objector during the Second World War said that the symbol was made up of the semaphore flag signals the letters "N" and "D" (Nuclear Disarmament”). These were enclosed in a circle representing the world.
He later wrote in a letter to Hugh Brock, editor of Peace News: “I was in despair. Deep despair. I drew myself: the representative of an individual in despair, with hands palm outstretched outwards and downwards in the manner of Goya’s peasant before the firing squad. I formalized the drawing into a line and put a circle round it.” However he may have misremembered the painting because as seen below the figure has his hands raised above his head.
Francisco Goya, The Third of May, 1808 in Madrid, 1808, 1814-15,
In Holtom’s personal notes the designer wrote how he first turned the design into a badge. "I made a drawing of it on a small piece of paper the size of a sixpence and pinned it on to the lapel of my jacket”. The first proper badges were made by Eric Austin of Kensington CND using clay. They were distributed with a note claiming that, in the event of a nuclear war, the fired pottery badges would be among the artifacts to survive a nuclear blast.
An original CND ceramic badge via http://www.cnduk.org/about/item/435-the-cnd-symbol
Although it was specifically designed for the CND copyright over the symbol was never enforced. It was available to be freely used by anyone leading to it's adoption internationally as a general symbol of peace. Recently, in November 2015, the symbol was modified by the French illustrator Jean Jullien in the aftermath of the terrorist attacks in Paris. Like Haltom before him Julien made his symbol free for all to use.
Peace for Paris Badge