Some 95% of the recorded population in Domesday Book belonged to the ranks of the peasantry.
The detailed record of the peasant classes in Domesday Book provides the first evidence in English history of their numbers and distribution. Domesday also indicates something of the variety of rural occupations, recording such diverse occupations as bee-keepers, carpenters, cowmen, fishermen, foresters, iron-workers, millers, potters, salt-workers, shepherds, swineherds, and others. Despite its many imperfections, therefore, Domesday Book is an indispensable source for the social structure of early English society.
Domesday Book also provides some evidence for the impact of the Conquest on the peasant classes. Since they are only normally enumerated for 1086, this evidence is patchy and open to different interpretations. Most historians have concluded from this silence that the peasantry was largely unaffected by the Conquest, merely continuing their labours for a different set of masters. Maitland, however, made out a persuasive case for viewing the Conquest as as much a catastrophe for the peasants as for their native lords: they were 'thrust out, or rather thrust down', and their history was 'divided into two parts by the red thread of the Norman Conquest'. Many individual details point to this conclusion, most persuasively perhaps the heavy premiums extracted from the peasantry over and above the customary manorial rents. Elsewhere, the separate holdings of large numbers of peasant proprietors were merged to make more substantial manors for Norman lords. What happened to these men and their heirs is not recorded. They cannot all have been killed or exiled. The most likely fate of the majority is to have been absorbed into the manorial peasantry, surviving as one entry vividly records 'harshly and wretchedly' (BUK 17,16). In Maitland's words, the peasantry 'were handed over to new lords who were free in fact, if not in theory, to get out of them all that could be got without gross cruelty'. This view has not been convincingly rebutted.
Domesday Book also provides the earliest census-like data upon which to base estimates of the total population of the country. Since it records heads of families rather than individuals, excludes the four northern counties, self-evidently omits many substantial groups - garrisons, noble households, clergy, - and records many others erratically, calculating the total population from its data can be no more that a controlled exercise in 'guestimating'. As the only available data, however, it cannot be ignored. The most recent examination of the problem gives 1,900,000 as the most likely total, rising to 2,000,000 if more generous allowance is made for omissions. A figure much higher than that cannot be justified on the data in Domesday Book.
It seems unlikely that this scrupulous calculation can be significantly improved upon. But it does pose a problem of its own. According to recent estimates, the population of late Roman Britain was as high as 4-5 million. The Domesday total therefore implies earlier population decline on a scale that many historians would find unable to accept, particularly since all available indicators point to economic and demographic expansion for at least three centuries prior to 1086 - perhaps longer - implying a demographic catastrophe in early Anglo-Saxon England far worse than the Black Death of the fourteenth century.
For the depression of the peasantry, see F.W. Maitland, Domesday Book and beyond (1897). H.C. Darby, Domesday England (1977), analyses the main classes of the population and their distribution with due regard to the imperfections of the record; Reginald Lennard, Rural England, 1086-1135: a study of social and agrarian conditions (1959), is important for the economic basis of the main groups within the peasantry; and J.S. Moore, '"Quot homines?": the population of Domesday England', Anglo-Norman Studies, vol. 19 (1997), pages 307-34, is the most recent systematic attempt to calculate the total population.