Paracelsus, also known by his full name Philippus Aureolus Theophrastus Bombastus von Hohenheim (1493–1541), was a Swiss-German physician, alchemist, natural philosopher, and one of the most controversial medical reformers of the Renaissance. He became famous because he challenged the authority of Avicenna, Galen, and Celsius, and the contemporary university medicine, argued that physicians should learn from direct experience, and promoted the use of chemical and mineral remedies. His importance lies especially in the connection he made between medicine and chemistry, which helped prepare the way for iatrochemistry, pharmacology, toxicology, and modern ideas about dosage. Britannica describes him as a physician and alchemist who “established the role of chemistry in medicine” and notes his famous surgical work Der grossen Wundartzney of 1536.