In 1985, the American pop artist Andy Warhol embarked upon his largest and most ambitious portfolio of screen prints. Entitled Reigning Queens, he sought to produce monumental images of each of the four ruling female monarchs of the day. In the case of Queen Elizabeth II, he based his prints on the official photograph taken by Peter Grugeon at Windsor Castle on 2 April 1975, and released for the Silver Jubilee in 1977.