The world-famous peace symbol, which turned 50 on April 4, 2008, was the brainchild of a British designer seeking a simple but powerful emblem for an anti-nuclear-weapons march in London in 1958. The symbol, which superimposes the semaphore signals for N (nuclear) and D (disarmament), caught on worldwide and quickly became a universal touchstone for the causes of peace and nonviolence.
A new National Geographic book, Peace: The Biography of a Symbol by photographer Ken Kolsbun and journalist Michael S. Sweeney, takes a look at the famous pictogram.
Here, a skywritten peace sign drifts above peace activist and folk singer Arlo Guthrie during a 1969 show at Tufts University in Medford, Massachusetts.
See photos of the history of the peace symbol, from National Geographic.