Polybius is still one of our main sources of information about the
Roman constitution. But, more important for present purposes,
Polybius's work enjoyed great success in Rome and exercised
enormous influence on Roman political thought. The Romans
recognized themselves in the picture that this Greek had painted of
their institutions. Indeed, the key political works of Cicero, De
Republica, De Legibus, and De Oratore, bear the mark of the conceptualization
put forward by Polybius.