In early medieval Europe, monasteries tended to become local centres of medical knowledge, and their herb gardens provided the raw materials for simple treatment of common disorders. Herbalists used to wander and provide herbal remedies to the sick and needy. Particularly well-known herbalists of medieval Europe were the so-called wise-women, who prescribed herbal remedies often along with spells and enchantments. However with the wave of missionary movement in the late Middle Ages such women who were knowledgeable in herblore became targets of the witch hysteria. One of the most famous women in the herbal tradition was Hildegard of Bingen, a 12th century Benedictine nun who wrote a medical text called Causes and Cures.