The Domesday Book (IPAEng: ˈduːmzdeɪ bʊk, also known as Domesday, or Book of Winchester) was the record of the great survey of England completed in 1086, executed for William I of England, or 'William the Conqueror'. The survey was similar to a census by a government of today. While spending Christmas of 1085 in Gloucester, William "had deep speech with his counsellors and sent men all over England to each shire ... to find out ... what or how much each landholder had in land and livestock, and what it was worth" (Anglo-Saxon Chronicle).

One of the main purposes of the survey was to determine who held what, and what taxes had been liable under Edward the Confessor; the judgment of the Domesday assessors was finalwhatever the book said about who held the material wealth, or what it was worth, was the law, and there was no appeal. It was written in Latin, although there were some vernacular words inserted for native terms with no previous Latin equivalent, and the text was highly abbreviated. The name Domesday comes from the Old English word dom (of which the Modern English doom is descended), meaning accounting or reckoning. Thus domesday, or doomsday, is literally a day of reckoning, meaning that a lord takes account of what is owed by his subjects. Christians believe that in the Last Judgment as recorded in Revelation, Christ will carry out a similar accounting of one's deedshence the term doomsday also refers to this eschatological event.

In August 2006, a complete online version of Domesday Book was made available for the first time by the UK's National Archives.

The Domesday Book

Despite its name, Little Domesday is actually larger — as it is far more detailed, down to numbers of livestock. It has been suggested that Little Domesday represents a first attempt, and that it was found impossible, or at least inconvenient, to complete the work on the same scale for Great Domesday.

For both volumes, the contents of the returns were entirely rearranged and classified according to fiefs, rather than geographically. Instead of appearing under the Hundreds and townships, holdings appear under the names of the local barons, i.e. those who held the lands directly of the crown in fee.

In each county, the list opened with the holdings of the king himself (which had possibly formed the subject of separate inquiry); then came those of the churchmen and religious houses; next were entered those of the lay tenants-in-chief (barons); and last of all those of women, of the king's serjeants (servientes), of the few English thegns who retained land, and so forth.