The fourth plinth

The fourth plinth on the northwest corner was intended to hold a statue of William IV, but remained empty due to insufficient funds. Later, agreement could not be reached over which monarch or military hero to place there.

In 1999, the Royal Society of Arts conceived the idea of the Fourth Plinth Project, which temporarily occupied the plinth with a succession of works commissioned from three contemporary artists. These were:

• Ecce Homo, by Mark Wallinger (1999)

• Regardless of History, by Bill Woodrow (2000)

• Monument, by Rachel Whiteread (2001)

Wallinger's Ecce Homo — whose title, in Latin, means "behold the man", a Biblical reference — was of a life-sized man. Atop the huge plinth, designed for larger-than-life statuary, it looked minuscule. Some commentators said that, far from making the man look insignificant, his apparent tininess drew the eye powerfully; they interpreted it as a commentary on human delusions of grandeur.

Whiteread's Monument, by an artist already notable for her controversial Turner Prize-winning work "House" and the Judenplatz Holocaust Memorial in Vienna, was a cast of the plinth in transparent resin, and placed upside-down on top of the original. Following the exhibition project, some wished to see it continue in this role.

Various companies have used the plinth (often without permission) as a platform for publicity stunts, including a model of David Beckham by Madame Tussauds. The London-based American harmonica player Larry Adler jokingly suggested erecting a statue of Moby Dick, which would then be called the "Plinth of Whales".

The best use of the fourth plinth remains the subject of debate. On March 24, 2003 an appeal was launched by Wendy Woods, the widow of the anti-apartheid journalist Donald Woods, hoping to raise £400,000 to pay for a nine-foot high statue of Nelson Mandela by Ian Walters. The relevance of the location is that South Africa House, the South African high commission, scene of many anti-apartheid demonstrations, is also located on Trafalgar Square.

A committee convened to consider the RSA's late-1990s project concluded that it had been a success and "unanimously recommended that the plinth should continue to be used for an ongoing series of temporary works of art commissioned from leading national and international artists" [2]. After several years in which the plinth stood empty, the new Greater London Authority assumed responsibility for the fourth plinth and started its own series of temporary exhibitions:

• Marc Quinn: Alison Lapper Pregnant (September 15, 2005)

• Thomas Schutte: Hotel for the Birds (scheduled for April 2007)

Quinn's Alison Lapper Pregnant is a 3.6m marble torso-bust of Alison Lapper, an artist who was born with no arms and shortened legs due to a condition called phocomelia.

A television ident for the television station Channel 4 shows a CGI Channel 4 logo on top of the fourth plinth.

Pigeons

People feeding the pigeons, circa 1993

The square is a popular tourist spot in London, and used to be particularly famous for its pigeons (Rock Pigeons). Feeding the pigeons was a popular activity with Londoners and tourists. The National Portrait Gallery displays a 1948 photograph of Elizabeth Taylor posing there with bird seed so as to be mobbed by birds. The desirability of the birds' presence has long been contentious: their droppings look ugly on buildings and damage the stonework, and the flock, estimated at its peak to be 35,000, was considered to be a health hazard. In 1996, police arrested one man who was estimated to have trapped 1500 birds for sale to a middleman; it is assumed that the birds ended up in the human food chain.

In 2000, the sale of bird seed in the square was controversially terminated and other measures were introduced to discourage the pigeons, including the use of trained falcons. Supporters of the pigeons and some tourists continued to feed the birds, but, in 2003, Ken Livingstone enacted by-laws to ban the feeding of pigeons within the square. There are now relatively few birds in Trafalgar Square and it is used for festivals and hired out to film companies, in a way that was not feasible in the 1990s.

Trafalgar Square from the National Gallery (looking south).

Trafalgar Square, 1908.