An opinion concerning Old Latin, of a Roman man of letters in the middle Republic, survives: the historian, Polybius, read "the first treaty between Rome and Carthage", which he says "dates from the consulship of Lucius Junius Brutus and Marcus Horatius, the first consuls after the expulsion of the kings". Knowledge of the early consuls is somewhat obscure, but Polybius also states that the treaty was formulated 28 years before Xerxes I crossed into Greece; that is, in 508 BC, about the time of the putative date of the founding of the Roman Republic. Polybius says of the language of the treaty "the ancient Roman language differs so much from the modern that it can only be partially made out, and that after much application by the most intelligent men".