Pythagoras Pythagoras was a Greek mathematician. He was born on the island of Samos, Ionia, Greece, circa 580 BC, to a father who is known to either have been a merchant or a signet-engraver. He lived most of his life in Croton, Italy, and here, where he quickly gained a strong influence over the inhabitants, he established the religion of Pythagoreanism. It was an extremely secretive cult, and was greatly concerned with mathematics and science along with religious beliefs. His followers were generally wealthy aristocrats. His religion carried on until approximately 300 BC, carried on by disciples, until it gradually died out. He is also credited with founding a school known as The Semicircle, the Pythagorean School of Mathematics in Crotona, and the Italic School of Philosophy. He lived in the classical period, which greatly celebrated and encouraged the study of mathematics. Samos was once known for rich residents, and Pythagoras was no exception. The land of Greece was separated into hundreds of generally republican city-states. This allowed for a large degree of freedom that encouraged free thinking. He is credited with the discovery of, aside from the Pythagorean Theorem, the diatonic scale, and that if the tension of a string is doubled, or length of a string is halved, then the sound of the string will go up an octave. His most famous discovery is the Pythagorean Theorem, which is used to find any remaining side of a triangle if two side lengths are known.