England's terrain mostly comprises low hills and plains, especially in central and southern England. However, there are uplands in the north (for example, the mountainous Lake District, Pennines, and Yorkshire Dales) and in the south west (for example, Dartmoor and the Cotswolds). The former capital of England was Winchester until replaced by London in 1066. Today London is the largest metropolitan area in the United Kingdom and the largest urban zone in the European Union by most measures. England's population is about 53 million, around 84% of the population of the United Kingdom, and is largely concentrated in and around London, the South East, and conurbations in the Midlands, the North West, the North East and Yorkshire, which each developed as major industrial regions during the 19th century. The Kingdom of England – which after 1284included Wales – was a sovereign state until 1 May 1707, when the Acts of Union put into effect the terms agreed in the Treaty of Union the previous year, resulting in a political union with the Kingdom of Scotland to create the new Kingdom of Great Britain.[11][12] In 1801, Great Britain was united with the Kingdom of Ireland through another Act of Union to become the United Kingdom of Great Britain and Ireland. In 1922, the Irish Free State was established as a separate dominion, but the Royal and Parliamentary Titles Act 1927 reincorporated into the kingdom six Irish counties to officially create the current United Kingdom of Great Britain and Northern Ireland.