Rome now turned her arms against Veii, which was about two German miles and a half distant, and nearly one German mile in circumference: its boundary must have reached as far as the Janiculum. This city was a thorn in the side of Rome, and until she had overthrown this rival, she could never be great. Fidenæ, which is called an Etruscan town, but was a Tyrrhenian one, is represented from the earliest times, even under Romulus already, as being involved in war with Rome: it lay one German mile above Rome on the Tiber. It was either in 320 or 329, that the Fidenates rose against the Roman _coloni_ and expelled them. Two wars are related here, according to all appearances put in the wrong place: the detailed account occurs at least once too much; probably it belongs to the year 329. In 320, hostilities may likewise have taken place; this is at all events the time fixed upon by Diodorus, whom we may follow. We must look upon these _coloni_ as a garrison of settlers who had their own hides of land. Three Roman ambassadors appeared at Fidenæ; and the inhabitants were called upon to justify themselves, and to reinstate the _coloni_. This seemed to them so unreasonable, that they slew the ambassadors, and threw themselves into the arms of the king of Veii, Lars Tolumnius; for all the Etruscan towns had a regal government, the king being elected for life. Tolumnius came across the Tiber to their assistance; and since the Romans, as the conquerors of the Æquians and Volscians, were now formidable to the neighbours, the Capenates and Faliscans, Oscan tribes, who had maintained themselves in those parts against the Tyrrhenians, hastened likewise to help the Fidenates. This host struck terror into the Romans; it lay one mile from Rome, being separated from it by the Anio only. A dictator was appointed, and he chose the military tribune A. Cornelius Cossus as Magister Equitum. The battle was a lucky one, and Cornelius Cossus slew the Veientine king Tolumnius, to whose charge, no doubt unjustly, the murder of the ambassadors was laid. The emperor Augustus with regard to it made the remark to Livy, that Cossus, on the strength of these _spolia opima_, had taken upon himself consular dignity; for on the armour he had called himself consul. This is a later addition in Livy, which, however, is left quite detached, or otherwise he must have placed the event seven years later. After this victory, Fidenæ was taken and razed to the ground; the _ager Fidenas_ became _ager publicus_. With the Veientines a truce was made, which was quite seasonable for the Romans, as it enabled them to begin by completely crushing the Æquians and Volscians. Towards the end of the armistice, the Veientines sent to the other Etruscan peoples for aid against the Romans. Yet it was refused them, inasmuch as from another side, on the Apennines, a far more dangerous enemy had appeared, which like a horde of invading Turks destroyed every thing before it, namely the Gauls.