The most probable estimate of the population at the beginning of the fourteenth century, gives the number at about 2,350,000. For many reasons it appears likely that population was not at this date increasing at a very rapid rate. Famines, notably those of 1315 and 1321, the absence of sanitary and medical skill, and the insecurity of life must all have tended to keep down the increase of numbers. It is, moreover, an observed fact that, among a peasant proprietary, population does not increase faster than the sustenance which has to support it. It is difficult to estimate what power of expansion there may have been through reclamation of waste land; there is no evidence, however, that agricultural skill was at all progressive. Root crops and grasses were entirely unknown. These, in fact, were not introduced into England till the seventeenth century. While agriculture rested under the disadvantage of the most primitive form of the common field system, it is not likely that increasing wealth offered much encouragement to an increase of population. There is no evidence, in fine, that anything in the nature of over-population existed at the time.

In 1348–1349, at a period when the numbers of the people were by no means excessive, the country was visited by the terrible calamity of the Black Death. Various computations are given of the mortality that ensued.