The bovate was both a unit of assessment and a customary peasant landholding unit found in most of the Danelaw counties. The word bovate is derived from bos, Latin for an ox; and since there were eight oxen to the standard Domesday plough team, which could notionally plough a ploughland of 120 acres in an agricultural year, the bovate was considered to contain 15 acres.
Although this formulae holds good for the fiscal system, fiscal acres could bear a variable relationship to customary acres on the ground. Since customary acres were normally composed of scattered furlong strips whose size varied according to the nature of the soils and the shape of the fields, customary bovates could vary in size from area to area, or even within the same manor.
Despite variations in size, however, individual bovates could, like other peasant holdings, remain fixed in size over generations, even centuries, their integrity maintained by the power of the lord or the customs of the manor. They provided the stable base for both the manorial and the assessment systems.
For more detail, see Frederic Seebohm, The English village community (fourth edition, 1915); J.H. Round, Feudal England (1895); F.W. Maitland, Domesday Book and beyond (1897); Cyril Hart, The Danelaw (1992); and Rosamond Faith, The English peasantry and the growth of lordship (1997).