Who is Pythagoras from A History of Western Philosophy and what is their importance?

Pythagoras was born in Samos that competed commercially with Miletus around 532 BC during the rule of Polycrates reigning between 535 BC and 515 BC. Polycrates murdered his brothers and engaged in piracy also profiting from the submission of Miletus to Persia. Pythagoras was the son of Mnesarchos. He went to Croton that conquered Sybaris in 510. In Croton he founded a society of disciples that influenced Croton citizens.