The prosecution of witchcraft generally became more prominent in the late medieval and Renaissance era, perhaps driven partly by the upheavals of the era – the Black Death, the Hundred Years War, and a gradual cooling of the climate that modern scientists call the Little Ice Age (between about the 15th and 19th centuries). Witches were sometimes blamed. Since the years of most intense witch-hunting largely coincide with the age of the Reformation, some historians point to the influence of the Reformation on the European witch-hunt.