The concept of a census – a count of every member of a population – is almost as ancient as civilisation. The Babylonians recorded a population count on clay tiles from 4000BC. The Egyptians collected census data from 2500BC to inform projects such as the construction of the pyramids and the reassignment of land after the flooding of the Nile.
And, as every child who’s performed the nativity knows, the Romans required everyone to return to their place of birth for a count every five years to inform tax collection from the 6th century BC.
