Major setbacks occurred at the end of the thirteenth century and continued into the fourteenth, when population expansion and declining crop yields coincided with a devastating and widespread plague, the Black Death (1348–1349). This had a major impact on population numbers—which dramatically declined—and on both society and economy. Immediately following an economic crisis, a period of crop failure, and an intensification of criminal activity (which may, perhaps, have been linked to fluctuations in food prices), the plague was devastating in its effects, and forms a turning point in the history of medieval England. Nor was the Black Death an isolated event; further pestilence struck in the 1360s, accentuating the problems.
International School of Central Switzerland on 01 Apr 13"The current paper surveys and analyzes the ecological and economic crisis of 1093- 1096, as the prelude to the First Crusade, chiefly in its "popular" form. The pestilence of 1093-1094, drought and famine of 1095 have increased the religious zeal and social violence of the popular masses in regions of Germany, the Low Countries and France. This combination has turned into the (failed) crusade. The collective behaviour of the crusading rustics reflects their economic distress, religious zeal and violent mood, at the same time."