These fiscal acres which could bear a variable relationship to the 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, virgates could vary in size from area to area, or even within the same manor.
Despite variations in size, however, individual virgates 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); and Rosamond Faith, The English peasantry and the growth of lordship (1997).