Gerolamo (or Girolamo, or Geronimo) Cardano (; ; ; 24 September 1501 21 September 1576) was an Italian Renaissance mathematician, physician, astrologer, philosopher and gambler. He wrote more than 200 works on medicine, mathematics, physics, philosophy, religion, and music. His gambling led him to formulate elementary rules in probability, making him one of the founders of the field.