Sir Isaac Newton (1643-1727), English physicist, mathematician and astronomer. Newton's most famous work is his Principia Mathematica (1687) in which he stated his universal laws of motion and defined his law of universal gravitation. This would form the basis of physics for the next two hundred years. Newton also studied the spectrum of light, showing that it was a mixture of colours, and he invented the reflecting telescope. In mathemetics, his achievements included developing calculus. He was President of the Royal Society from 1703 to 1727, and was knighted in 1705. This artwork was the frontispiece portrait for the 3rd edition (1726) of Principia Mathematica.