Derived from the Greek elements παν (pan) meaning "all" (genitive παντος) and λεων (leon) meaning "lion". This was the name of a 2nd-century BC king of Bactria. It was also borne by Saint Pantaleon (also called Panteleimon), a doctor from Asia Minor who was martyred during the persecutions of the Roman emperor Diocletian in the early 4th century. He is a patron saint of doctors and midwives.