So far, seven contemporary artists have presented work on the fourth plinth in Trafalgar Square. The plinth which was originally designed to house an equestrian statue of William IV in 1841 stood empty after this became too expensive leaving a gap to be filled for nearly 150 years.

The ICA is now presenting an exhibition just a stones throw from the illustrious plinth which contains 21 moquettes chosen by the Fourth Plinth Commissioning Group (FPCG) along with other works not chosen. The first works were chosen by the RSA including the most traditional of them all, Ecce Homo by Mark Wallinger in 1999. The figurative structure is a life size depiction of Christ in the crown on thorns to coincide with the millennial anniversary of his birth. It was constructed out of white marble resin, which seems to me to fit in with the other three plinths the most easily. From this resin structure we are shown a vast array of offerings from Yinka Shonibare’s Nelson’s Ship is a Bottle to the future Hahn/Cock by Katharina Fritsch, an electric blue cockerel, the national symbol of France, a daring idea for a square celebrating the British victory over the French.

Some artists such as Marc Quinn have had a more ‘human’ approach, presenting Alison Lapper Pregnant in 2005, an armless pregnant woman which was later replicated at the opening ceremony of the Paralympic games. Four years later in 2009, Antony Gormley’s One & Other saw 2,400 people occupy the plinth in a grand display of public participation in an area of London which sees forty thousand visitors every hour.

The ICA also lets us see archival material from the Mayor of London’s offices and the RSA as well as ideas not chosen. These include Sokari Douglas Camp’s No-o-war-r No-o-war-r and Jeremy Deller’s The Spoils of War, which was perhaps not chosen for fear of being too overtly political.

This exhibition allows Londoners to view the artworks together for the first time while also considering what makes a successful monument. A brilliant display of contemporary history. Currently, a small boy rides a golden rocking horse on top of the plinth. Elmgreen and Dragset’s child will soon be replaced by a giant chicken. What next?

Fourth Plinth: Contemporary Monument is on display at the ICA until 20 January