After the war, London suffered from a trend first witnessed in America, what was referred to as "counter-urbanization" by human geographer Brian Berry in the 1970s. People were choosing more and more to not live in cities. In London's case, many chose to live in the city's sprawling suburbs and the "new towns" first created for those displaced by the war.
However, by the mid-1980s, that began to change. London's population began to rise, slowly at first, and then much quicker. Predictions from the ONS said it will reach 10 million within 15 years and keep rising after. London's reputation as an international city continues to grow: It may no longer be the center of the empire, but it's now the largest city in the European Union.