The most recent census took place on Sunday 27 March 2011, and it followed a rich tradition.
Governments of every era have recognised the need to collect information on their most valuable asset - their people. The Babylonians and the Chinese held censuses mainly for military and taxation purposes. The Egyptians collected information on the population so that they could plan armies of people to build the pyramids and to redistribute land following the annual flooding of the Nile.
The first thorough survey of England was in 1086 when William the Conqueror ordered the production of the Domesday Book. This detailed inventory of land and property was a massive undertaking at the time. It took many years to complete and provides us with a remarkable picture of life in Norman Britain.
In Tudor and Stuart times, bishops were made responsible for counting the number of families in their diocese, but Britain was very reluctant to adopt the idea of a regular official census.
While Quebec held its first official census in 1666, Iceland in 1703 and Sweden in 1749, Britain was slow to follow suit. Some churchgoers believed that any type of people count was sacrilegious. They quoted the notorious census ordered by King David in Biblical times, which was interrupted by a terrible plague and never completed. Others said that a population count would reveal the nation's strengths and weaknesses to foreign enemies.
Towards the end of the eighteenth century however, it became increasingly obvious that there was little idea about the number of people living in Britain.
Opposition to an official census finally withered away after demographer Thomas Malthus published his essay on the 'principle of population' in 1798. Malthus caused great concern by suggesting that population growth would soon outstrip supplies of food and other resources. Unable to support itself, Britain would be hit by famine, disease and other disasters.
Concerned at this alarmist view of the future, people began to see the need for a census. Parliament passed the Census Act in 1800 and the first official census of England and Wales was on 10 March 1801.
Information was collected from every household by the Overseers of the Poor, aided by constables, tithingmen, headboroughs and other officers of the peace. The Act also applied to Scotland, where the responsibility for taking the count was placed on schoolmasters. In Ireland, the first modern census was taken 20 years later, in 1821
The first official head count revealed that Great Britain's population at the time was 9 million. Previous estimates had varied between 8 and 11 million. Information about every person in the land was processed by an army of clerks using nothing more than pens and paper. Technology made census taking simpler in 1911, when punch cards and mechanical sorting and counting machines were introduced. Computers were first used in the 1961 Census.
The census taken in 1841 is widely regarded as the first truly modern census, when the first Registrar General of England and Wales, John Lister, was made responsible for organising the count. The task of counting was passed on to local officers of the newly created registration service.
For the first time, the head of each household was given a form to complete on behalf of everyone in the household on a certain day. This system has stood the test of time, and it still forms the basis of the method we use today. In Scotland there was no local registration service until 1855. A separate Act in 1860 gave the Registrar General for Scotland responsibility for taking the 1861 Census. Prior to the passing of the Northern Ireland Census Act 1969, censuses in Northern Ireland were taken under the authority of separate Acts.
Since 1801 there has been a census every ten years except in 1941, during the Second World War. The basic principles of census taking remain the same, though new questions have been added and others have been omitted. Up until 1911 the Government needed to introduce a new Census Act for every census held. This was changed by the 1920 Census Act which made it possible for the Government to hold a census at any time, once Parliament has approved the necessary 'secondary' legislation which lays out the details of a particular census, but no sooner than five years after the last census.
The 2011 Census was the first that people could complete online. Each household had a unique internet access code on the front of their questionnaire that they could use to access and complete their online census form. The way the census is carried out and the questions asked have changed over time to adapt to new technologies and the needs of society.
