The 1321 lepers' plot was an alleged conspiracy of French lepers to spread their disease by contaminating water supplies, including well water, with their powders and poisons. According to the American historian Solomon Grayzel, lepers were the most abused group of people during the Middle Ages: they were thrown out of settlements and treated as wild animals due to the widespread belief that their disease was highly contagious. However, other historians have contested such a view, pointing out that lepers often lived within communities in leper houses (leprosaria) and were supported by charitable donations.