Pythagoras

Pythagoras left the Greek island of Samos around 570 BC and travelled to Croton in southern Italy circa 530 BC, where he founded a school steeped in secrecy, communal living, and ascetic discipline. In antiquity he was credited with discovering the Pythagorean theorem, the five regular solids, the sphericity of the Earth, and the identity of the morning and evening stars as Venus - though modern scholars suspect many of these breakthroughs came from his followers, like Hippasus and Philolaus. The teaching most firmly his own: metempsychosis, the belief that immortal souls enter new bodies after death. After Croton crushed the rival city of Sybaris around 510 BC, his followers clashed with democratic factions; their meeting houses were torched. Pythagoras either died in the violence or fled to Metapontum, where he may have ended his days. His ideas shaped Plato and Aristotle, echoed through the Middle Ages, and nudged Copernicus, Kepler, and Newton centuries later.