The healing properties of Bath’s mineral springs were said to have been discovered by Prince Bladud around 900BC. Banished from court because of his leprosy, he became a swineherd. When the pigs were suffering from cracked skins he took them done to a marsh where the warm water gave off steam which healed them so completely that Bladud immersed himself and cured his leprosy.
You will find Bladud references dotted around Bath (e.g. the Bladud Arms pub and Bladud Buildings)