In Denmark the crisis of the Late Middle Ages was characterised by deserted farms, declining rents, and abandoned churches. As was the case in other countries in northwestern Europe, the peak of the crisis lagged behind the Black Death by a half century. Thus, without denying the immediate, ferocious impact of the first epidemic wave of the plague, scholars have looked for a further explanation of the crisis. To many historians who have seen the population decline as the central factor, there was an answer to be found in the Malthusian explanation of M. M. Postan (according to which the decline began long before the plague) combined with demographer J. C. Russell's elucidation of the effects of the Black Death along with subsequent epidemics. This, for instance, was the solution offered by C. A. Christensen in 1964. 

The present article questions the value of the sources which Danish historians have used to demonstrate a population decline prior to 1350. This source material is simply too inadequate to support any claims whatsoever in the field of demographic research. The Black Death, on the other hand, is relatively well documented, however little the sources have to say about mortality. Since Denmark, nevertheless, lay directly in the main path of the plague, there is no reason to suppose it was less ravaged than other countries. In England, the country on which the best research has been done, mortality was certainly very high. 

Modern Danish research has showed little interest in the plague. One of the main reasons for this is presumably the failure to document the subsequent epidemics. In the sparse chronicle literature of the period there is only a single reference to a later plague, the one in 1360. But a closer study of the anniversary (of deaths) registers of the cathedrals in Ribe, Roskilde and Lund, which are also the best sources on the plague in 1350, shows that the plague returned in 1360 and 1368/69 (the years of the second and third epidemics in Europe) as well as in 1379. And each time, as in 1350, it came in later summer or early autumn. Except for Ribe in 1350, the number of deaths registered was small, but in relation to the figures for each month from 1301 to 1390 the deviations are statistically certain and demonstrate the occurrence of the plagues. Russell's theory on the cumulative impact of the plagues is thus a plausible explanation of the many deserted farms in Denmark around 1400. 

Translated by Michael Wolfe