William Gilbert, also known as Gilbard (Colchester, England, May 24, 1544 - London, England, November 30, 1603) was an English physician and a natural philosopher. He was an early Copernican, and passionately rejected both the prevailing Aristotelian philosophy and the Scholastic method of university teaching. After gaining his MD from Cambridge in 1569, and a short spell as bursar of St John's College, Cambridge, he left for practice in London and in 1600 was elected President of the College of Physicians (not by that point granted a royal charter). From 1601 until his death in 1603, he was Elizabeth I's own physician, and James VI and I renewed his appointment.
Scientifically, Gilbert is known for his investigations of magnetism and electricity. Gilbert is credited as one of the originators of the term electricity, and many regard him as the father of electrical engineering or father of electricity.
His primary work was De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure (On the Magnet and Magnetic Bodies, and on the Great Magnet the Earth) published in 1600. In this work he describes many of his experiments with his model earth called the terrella. From his experiments, he concluded that the Earth was itself magnetic and that this was the reason compasses pointed north (previously, some believed that it was the pole star (Polaris) or a large magnetic island on the north pole that attracted the compass).
The English word "electricity" was first used in 1646 by Sir Thomas Browne, derived from Gilbert's 1600 New Latin electricus, meaning "like amber". The term was in use since the 1200s, but Gilbert was the first to use it to mean "like amber in its attractive properties". He recognized that friction with these objects removed an "effluvium", which would cause the attraction effect in returning to the object, though he did not realize that this substance (electric charge) was universal to all materials.