A census of the population of England and Wales was first taken in 1801 and has been repeated at ten year intervals ever since, with the exception of 1941 when the second world war prevented it. Up to and including 1831 the census returns recorded only numbers of people without any names being given, and so are of little use to genealogists.

In the 1841 census a limited amount of personal information was given, including names, ages rounded down to the nearest 5 years, occupation, and an indication whether or not the individual was born within the county. For later censuses this was extended to include exact ages, marital status, relationships and places of birth. The returns are held by the Public Record Office (now known as the National Archives), but are not released for public inspection until 100 years after the census date. They can be inspected on microfilm at The National Archives at Kew, and many local record offices hold copies of the returns for their areas.

The original returns have now all been digitised so that they can be made available to researchers on the Internet. This means in practice that they are photographed, and the digitised photographic images can then be accessed by subscribers to a suitable service. This process includes provision of an on-line index, and is now complete for all censuses from 1841 to 1911 inclusive. These are now available on Ancestry  and on FindMyPast . Additionally the 1841, 1861 and 1871 Censuses are available on British Origins . In all cases a fee is payable. The 1901 census is also available on the National Archives site, www.1901censusonline.com  and the 1911 Census is available on the FindMyPast site referenced above, together with a dedicated site 1911 Census . Always a fee is payable.

The 1881 census has been placed on the Internet by the Church of Jesus Christ of Latter-day Saints (the Mormons), who have transcribed the entire census by hand into database form. This can be inspected free of charge at www.familysearch.org , but there are no images available on this site.

All the entries relating to persons with the surnames Debenham, Debnam and close variants in the England and Wales Census have been extracted from the returns for all Censuses from 1841 to 1911 inclusive, and are available to be searched on-line at the archives of the Guild of One-Name Studies.

• Transcription errors are more common than we would wish, particularly by the Enumerators when copying the householders' schedules into their books, and clearly there were mis-spellings on the original schedules as well. Where these are obvious they have been ignored and the correct entry substituted. Where there is doubt, the actual census entry is shown.
• The names Frances (female) and Francis (male) are frequently confused. I have always given the correct spelling for the gender.
• Frequently a second name is given just as an intitial, for example Sarah Jane is often shown as Sarah J. The full second name, when known, is given in the column headed Search Names, and a search on such a name will give the correct result.
• There are many variations on the surname, for example Debnan, Debman, Dibnam, Debnham, and others. The surname is entered as shown on the original census return, but in almost every case it refers in practice to a Debenham or a Debnam. In a few cases the name Debman has survived as a true variant, but this must be the subject of separate research.
• The column headed Schedule Number refers to the first column of the Enumerators' book pages, and is the number of the individual household schedule (these no longer survive for the censuses before 1911). Exceptionally, when the Enumerator's book refers to an institution such as a workhouse or military establishment, the number in the Schedule column is the line number on the relevant page.
• The information is provided in good faith, but no promises are made regarding accuracy or completeness.