First used in Ayurvedic medicine, blessed thistle eventually made its way to Europe. By the early sixteenth century, it had gained footing in European folk medicine and was cultivated widely in monastery gardens. Even the famous poet Shakespeare mentioned blessed thistle in his play Much Ado About Nothing.
Spiritually, blessed thistle is associated with purification and therefore used in purification baths. It is also believed that wearing a bit of it would protect one from evil. Further, it was associated with the planet Mars, the zodiac sign of Aries, and the element fire. Mostly, though, blessed thistle was popular in Medieval England, where King Charlemagne was supposedly visited by an angel revealed that everything from headaches and poor memory to the black plague and smallpox.