With
increasing industrialization, London's population grew rapidly throughout the
19th and early 20th centuries, and it was for some time in the late 19th and
early 20th centuries the most populous city in the world until overtaken by New
York City in 1925. Its population peaked at 8,615,245 in 1939 immediately
before the Second World War, but then declined to 7,192,091 at
the 2001 Census. However, the population then grew by just over a million
between the 2001 and 2011 Censuses, to reach 8,173,941 in the latter
enumeration.