In historic and modern usage, a hearth is a brick- or stone-lined fireplace, with or without an oven, used for heating and originally also used for cooking food. For centuries, the hearth was such an integral part of a home, usually its central and most important feature, that the concept has been generalized to refer to a homeplace or household, as in the terms "hearth and home" and "keep the home fires burning".
In a medieval hall, the hearth commonly stood in the middle of the hall, with the smoke rising through the room to a smoke hole in the roof. Later, such hearths were moved to the side of the room and provided with a chimney. In fireplace design, the hearth is the part of the fireplace where the fire burns, usually consisting of masonry at floor level or higher, underneath the fireplace mantel.
The word hearth derives from an Indo-European root, *ker-, referring to burning, heat, and fire (seen also in the word carbon). In archaeology, a hearth is a firepit or other fireplace feature of any period. Hearths are common features of many eras going back to prehistoric campsites and may be either lined with a wide range of materials, such as stone or left unlined. They were used for cooking, heating, and the processing of some stone, wood, faunal, and floral resources. Occasionally site formation processes--e.g., farming or excavation--deform or disperse hearth features, making them difficult to identify without careful study.
Lined hearths are easily identified by the presence of fire-cracked rock, often created when the heat from the fires inside the hearths chemically altered and cracked the stone. Often present are fragmented fish and animal bones, carbonized shell, charcoal, ash, and other waste products, all embedded in a sequence of soil that has been deposited atop the hearth. Unlined hearths, which are less easily identified, may also include these materials. Because of the organic nature of most of these items, they can be used to pinpoint the date the hearth was last used via the process of radiocarbon dating. Although carbon dates can be negatively affected if the users of the hearth burned old wood or coal, the process is typically quite reliable. This was the most common way to cook, and to heat interior spaces in cool seasons.
In the Byzantine Empire a tax on hearths known as kapnikon was first explicitly mentioned for the reign of Nikephorus I (802–811) although its context implies that it was already then old and established and perhaps it should be taken back to the 7th century AD. Kapnikon was a tax raised on households without exceptions for the poor.
In England, a tax on hearths was introduced on 19 May 1662. Householders were required to pay a charge of two shillings per annum for each hearth, with half the payment due at Michaelmas and half at Lady Day. Exemptions to the tax were granted, to those in receipt of poor relief, those whose houses were worth less than 20 shillings a year and those who paid neither church nor poor rates. Also exempt were charitable institutions such as schools and almshouses, and industrial hearths with the exception of smiths' forges and bakers' ovens. The returns were lodged with the Clerk of the Peace between 1662 and 1688.
A revision of the Act in 1664 made the tax payable by all who had more than two chimneys.
Hearth tax records are important to local historians as they provide an indication of the size of each assessed house at the time. The numbers of hearths are generally proportional to the size of the house. The assessments can be used to indicate the numbers and local distribution of larger and smaller houses. Not every room had a hearth, and not all houses of the same size had exactly the same number of hearths, so they are not an exact measure of house size. Roehampton University has an ongoing project which places hearth tax data in a national framework by providing a series of standard bands of wealth applicable to each county and city.
Published lists are available of many returns and the original documents are in the Public Record Office. The most informative returns, many of which have been published, occur between 1662-1666 and 1669-1674.