The fourth plinth is the northwest plinth in Trafalgar Square in central London. It was originally intended to hold an equestrian statue of William IV, but remained empty due to lack of funds. For over 150 years, its use was debated; in 1998, the Royal Society for the encouragement of Arts, Manufactures and Commerce (RSA) commissioned three contemporary sculptures to be displayed temporarily on the plinth. Shortly afterwards, Chris Smith, Secretary of State for Culture, Media and Sport, commissioned Sir John Mortimer to seek opinions from public art commissioners, critics and members of the public as to its future. Mortimer's final report recommended that there continue to be a rolling programme of commissioned temporary artworks rather than settle permanently on one figure or idea.

Trafalgar Square is a public square in the City of Westminster, Central London, established in the early 19th century around the area formerly known as Charing Cross. The square's name commemorates the Battle of Trafalgar, the British naval victory in the Napoleonic Wars over France and Spain that took place on 21st October 1805 off the coast of Cape Trafalgar.