Census Returns are probably the most useful of all sources for family history in that it is the only resource that brings together a whole household, often including extended family. The ages and places of birth can lead you to an individual’s birth certificate and/or baptism entry.
Census returns also enable local historians to obtain a complete record of the inhabitants of a place, and its occupational and social structure.
A census has been taken in England and Wales every ten years since 1801, with the exception of 1941, on account of war.
The information required on the census has increased over the years.