It was built between 1840 and 1843 to commemorate Admiral Horatio Nelson, who died at the Battle of Trafalgar in 1805. It consists of a 5.5m (18ft) statue of Nelson on top of a 56 m granite column. The top of the column is decorated with bronze acanthus leaves cast from British cannon. The square pedestal is decorated with four bronze panels, cast from captured French guns, depicting Nelson's four great victories.
The monument was designed by architect William Railton in 1838. His original 1:22-scale stone model is exhibited at the National Maritime Museum in Greenwich.
In May 2003 a base-jumper parachuted from the top of the column to draw attention to the Chinese occupation of Tibet.