Ab urbe condita
Titus Livius (Livy)
Livy. History of Rome, Volumes 1-2. Roberts, Canon, Rev, translator. London, New York: J. M. Dent and Sons; E. P. Dutton and Co., 1912.
Romulus thus became sole ruler, and the city was called after him, its founder. His[*](The Legend of Hercules and Cacus.) first work was to fortify the Palatine hill where he had been brought up. The worship of the other deities he conducted according to the use of Alba, but that of Hercules in accordance with the Greek rites as they had been instituted by Evander.
It was into this neighbourhood, according to the tradition, that Hercules, after he had killed Geryon, drove his oxen, which were of marvellous beauty. He swam across the Tiber, driving the oxen before him, and wearied with his journey, lay down in a grassy place near the river to rest himself and the oxen, who enjoyed the rich pasture.
When sleep had overtaken him, as he was heavy with food and wine, a shepherd living near, called Cacus, presuming on his strength, and captivated by the beauty of the oxen, determined to secure them. If he drove them before him into the cave, their hoof-marks would have led their owner in his search for them in the same direction, so he dragged the finest of them backwards by their tails into his cave. At the first streak of dawn Hercules awoke, and on surveying his herd and saw that some were missing.