The new towns in the United Kingdom were planned under the powers of the New Towns Act 1946 (9 & 10 Geo. 6. c. 68) and later acts to relocate people from poor or bombed-out housing following the Second World War. Designated new towns were placed under the supervision of a development corporation, and were developed in three waves. Later developments included the 'expanded towns': existing towns which were substantially expanded to accommodate what was called the "overspill" population from densely populated areas of deprivation.