CENSUS 1841-1901

In the 7th century, Dál Riata (now Scotland) was the first territory in what is now the UK to conduct a census, with what was called the "Tradition of the Men of Alba" (Senchus fer n-Alban). England took its first Census when the Domesday Book was compiled in 1086 for tax purposes.

Following the influence of Malthus and concerns stemming from his An Essay On The Principle Of Population the UK census as we know it today started in 1801. This was championed by John Rickman who managed the first four up to 1831, partly to ascertain the number of men able to fight in the Napoleonic wars. Rickman's 12 reasons - set out in 1798 and repeated in Parliamentary debates - for conducting a UK census included the following justifications:

'the intimate knowledge of any country must form the rational basis of legislation and diplomacy'

'an industrious population is the basic power and resource of any nation, and therefore its size needs to be known'

'the number of men who were required for conscription to the militia in different areas should reflect the area's population'

'there were defence reasons for wanting to know the number of seamen'

'the need to plan the production of corn and thus to know the number of people who had to be fed'

'a census would indicate the Government's intention to promote the public good' and

'the life insurance industry would be stimulated by the results.'

The census has been conducted every ten years since 1801 and most recently in 2001. The first four censuses (1801-1831) were mainly statistical (that is, they were mainly headcounts and contained virtually no personal information).

The 1841 Census, conducted by the General Register Office, was the first to record the names of everyone in a household or institution. However, their relationship to the head of the household wasn’t noted, although sometimes this can be inferred from the occupation shown (eg servant). Those under the age of 15 had their proper ages listed, but for those who were older the ages were supposed to be rounded down to the nearest five years, although this rule was not strictly adhered to. Precise birthplaces were not given - at best the birthplace can be narrowed down to the county in which the person was living.

From 1851 onwards the census shows the exact age and relationship to the head of household for each individual; the place of birth was also listed, but with varying degrees of precision. Sometimes those who were born abroad have the annotation B.S. or British Subject.

The censuses are reasonably accurate. However ages in particular are frequently shown incorrectly, though often the difference is only one year; in general the younger the individual the more accurate the age shown. Birthplaces often vary from one census to the next: a common error is to show the place where the census was taken as the birthplace, but most of the variations in birthplace can be accounted for by changes in geographical scale (for example, the nearest town being shown instead of the precise village, or a city being shown instead of the relevant suburb).

The censuses are also remarkably complete - though inevitably a small percentage of the population wasn’t recorded for one reason or another, and in some cases the records are missing or damaged (notably in 1861). Furthermore, all censuses of Ireland before 1901 have been lost or destroyed.

Because of World War II, there was no census in 1941. However, following the passage into law (on 5 September 1939) of the National Registration Act a population count was carried out on 29 September 1939, which was, in effect, a census.

The census is undertaken for the government by the Office for National Statistics (ONS) for policy and planning purposes, and statistical information is also sold to interested parties. Public access to the census returns is restricted under the terms of the 100-year rule and the most recent returns made available to researchers are those of the 1901 Census.

The 2001 census was the first year in which the government asked about religion. Perhaps encouraged by a hoax chain letter that started in New Zealand, 390,000 people entered their religion as Jedi Knight (more than either Sikhs, Buddhists or Jews), with some areas registering up to 2.6% of people as "Jedi". It was wrongly implied in emails that stating "Jedi" on the form would cause it to become an "official religion". No such thing exists in the United Kingdom. However, the director of reporting and analysis at the ONS stated that it may have helped with the collection process as it encouraged young people, who are often missed, to complete forms. (See Jedi census phenomenon.)

All of the British censuses from 1841-1901 have been transcribed and indexed and are available online; there is a joint project between the National Archives of Ireland and Library and Archives Canada to digitize the 1901 and 1911 censuses for the whole of Ireland, and it is possible this will be completed by the end of 2007.