It is well-known that Etruria, south of the Apennines, contained twelve ruling towns, to which the others were subject. We must not, however, suppose that there existed no more than twelve places deserving the name of towns, but they were twelve sovereign cities, and all the others were dependent upon them. This fact is certain and beyond all doubt. They were all situated within the district from the Apennines about Luna and the Tiber. But which of the Etruscan towns they were, is quite a different question; some of them are certain, others can be named only with probability, while others, again, can only be guessed. Descending from the north, we find the following towns, which Livy, in his account of the second Punic war, distinctly affirms, were ruling cities: Volaterrae, Populonia, Rusellae, and Tarquinii; and in the interior, Arretium, Perusia, Caere and Clusium. Four accordingly are wanting, either because they had perished, or because they had ceased to belong to the Etruscan nation. Veii and Vulsinii had been destroyed, and Capena had become a Roman municipium. But whether Capena ever was one of the sovereign cities, may seem doubtful. All these relations belong to so remote a period, and the notices we have of them in the ancient authors are so vague, that we must be extremely cautious. The case of Cortona is particularly doubtful. Livy, near the close of the first decad,[57] mentions it as an Etruscan town; but at the time of the second Punic war he does not name it among those which distinguished themselves by the support they gave to Scipio. Herodotus, in speaking of his own time, says that Cortona[58] was inhabited by Pelasgians who were foreign to the Tyrrhenians, that is, to the Etruscans and Ombricans. This is a great mystery, which it is impossible to solve with any degree of certainty. Had Cortona become Etruscan in the middle of the fifth century, while during the first half of the fourth it was still Tyrrhenian? or did Herodotus transfer to his own time that which was correctly applicable only to an earlier period? Different conjectures may be entertained as to why it is not mentioned in the second Punic war: Livy either forgot it, or the town had, perhaps, not been included in the general peace which the Etruscans concluded with the Romans at the time of the war with Pyrrhus; it is possible also that it may have concluded a separate peace, or that it had been conquered. For the books of Livy and Dionysius, containing the account of that period, are lost, and the brief extracts furnish no satisfactory information. We may, therefore, have recourse to several modes of explanation, but we must be cautious and not regard as certain what is merely possible.