Plutarch, Romulus
Bernadotte Perrin, Ed.

24. After this, a plague fell upon the land, bringing sudden death without previous sickness upon the people, and afflicting the crops with unfruitfulness and the cattle with barrenness. There was a rain of blood also in the city, so that many superstitious fears were added to their unavoidable sufferings. And when similar calamities visited the people of Laurentum, all agreed at once that it was the miscarriage of justice for the death of Tatius and the slain ambassadors which brought the wrath of heaven down upon both cities. [2] The murderers, therefore, were delivered up on both sides and punished, and the mischief visibly abated. Romulus also purified the cities with lustral rites, which they say are celebrated to this day at the Ferentine gate.

But before the pestilence had ceased, the people of Cameria attacked the Romans and overran their territory, thinking them incapable of defending themselves by reason of their distress. [3] Romulus therefore at once marched against them, overcame them in battle, and killed six thousand of them. He also took their city, transplanted half of the survivors to Rome, and sent to Cameria as colonists from Rome twice the number he had left there, and this on the first of August. So many citizens had he to spare after dwelling in Rome less than sixteen years. Among other spoils he brought also a bronze four-horse chariot from Cameria, and dedicated it in the temple of Vulcan. For it he had a statue made of himself, with a figure of Victory crowning him.