Polybius

Polybius (ca. 200–118 BC), Greek Πολύβιος) was a Greek historian of the Hellenistic Period noted for his book called The Histories covering in detail the period of 220–146 BC. He is also renowned for his ideas of political balance in government, which were later used in Montesquieu's The Spirit of the Laws and in the drafting of the United States Constitution.