Pythagoras of Samos is considered one of the first pure mathematicians. He founded the religious movement called Pythagoreanism in Croton, Italy. Very little is reliably known about Pythagoras' life and achievements due to information being recorded centuries later. He is best known for the Pythagorean theorem relating the sides of a right triangle, though some question how much he personally contributed to mathematics. The Pythagorean brotherhood he established was devoted to his religious and philosophical teachings.