Livy 1.5

Already then on the Palatine mountain they say was this Lupercal festival, (the hill was called) Pallantium from Pallanteum, an Arcadian city, afterward (lit. then) the hill was named Palatium.  Then Evander, who, from this race of Arcadians, held the territory many ages before, had instituted a festival brought in from Arcadia so that naked young men ran about for sport and wantonness, venerating Lycaean Pan, whom the Romans afterwards called Inuus.  [Huic] For those given over to this rite, because the festival was widely known, the thieves, on account of their anger over their lost plunder, set an ambush; although Romulus defended himself with force, but the captured Remus, and they handed over the captive to Amulius the king, accusing (him) impudently (lit. beyond (his crimes)).  [Crimini] They were giving for the charge mostly that attacks were being made by them on Numitor’s fields; then, with a band of youths having been collected, these were taking plunder in a war-like manner.  Thus Remus is given over to Numitor for punishment.

Now already for Faustulus from the beginning had been the hope that royal offspring was being brought up in his house: for he knew both that infants had been exposed by the king's command and that the time at which he had rescued them corresponded to this very (time); but he had not wanted to divulge the matter unseasonably (lit. adj.) unless through a fitting opportunity or through necessity.  Necessity came first.  [Ita] Thus driven by fear for Remus he disclosed the matter.  By chance * also, when he had Remus in his custody and had heard that they brothers were twins, by comparing both their ages and their bearing unlike servile (bearing),  the memory of his grandchildren had touched *Numitor’s mind; and he arrived at the same understanding so that it was hardly far but to recognize Remus.  [Ita] Thus a plot is woven for the king on all sides.  Romulus not with a group of youths, for he was not even equal to open force, but, with some ordered to come to the palace by another route at a set time, he makes an attack on the king and, from the home of Numitor, Remus helps with another band having been gathered.  Thus they kill the king.