Livy 1.4

But by the Fates had, as I believe, was owed the origin of such a great city and the beginning of the greatest empire after power of the gods.  The Vestal, overwhelmed by force, when she had produced twin offspring, names Mars the father of the uncertain issue, whether thus she thought or because a god as the author of her crime was more respectable.  [Sed] But neither gods nor men shelter either her or her offspring from royal cruelty.  The priestess, bound, is given into custody; he orders the boys to be thrown into the flowing water.

By some chance providentially, the Tiber had poured out over its banks in stagnant pools and could not be approached up to the course of the regular stream and gave the hope to those carrying that the boys could be drowned by the water, although languid.  Thus, as if carrying out the order of the king, the expose the boys in the nearest overflow where now the Ruminalis fig tree is – they say that it was called the Romularis.  [Vastae] Then there were vast wildernesses in these places.  The story is, when the shallow water had left the floating basket in which the boys were exposed on dry ground, a thirsty she-wolf from the mountains which were around had bent her course toward the boyish crying; she had provided her distended teats to the boys so gently that the master of the royal flock found her licking the boys with her tongue.  [Faustulo] They say his name was Faustulus.  By him to his cottage to his wife Laurentia (they boys) were given to be raised.  There are those who think that Larentia was so called among the shepherds from making her body common; thence the reason given to the story and miracle.

Thus born and thus brought up, as soon as their age matured, sluggish neither in the folds nor about the herds, wandered the woods in hunting.  Hence with strength in bodies and minds having been developed, already they not only face wild animals but make attacks on thieves loaded with booty and divide the captured goods among the shepherd and, with these celebrate serious things and jovial with a flock of youths growing day by day.