Trafalgar Square, built to celebrate the victorious forces of the British state and armed forces, has been a centre of political dissent since its opening in 1844, despite a ban on rallies until the 1880s. The Chartist Movement began there in 1848, and over a century later, the Campaign for Nuclear Disarmament started its first Aldermaston march in the square. In 1990, the Poll Tax riots started with a 200,000 strong rally in Trafalgar Square. The riots were the culmination of a movement that brought down Thatcher’s government. More recently, in 2009 it was the site of a two week occupation by the Camp for Climate Action, protesting the UN Climate Conference in Copenhagen.