Werewolf stories existed in Europe as long ago as Ancient Roman times, but the ways people imagined them changed. Whereas for much of the Middle Ages, werewolves retained some of their sympathetic human nature, by the late 15th century they began to figure as evil servants of the devil. Some men were even executed for their lycanthropy.
Source: The Medieval Werewolf https://warwick.ac.uk/fac/arts/ren/researchcurrent/researchblog/werewolf/
