Titus Livius (Livy), The History of Rome, Book 1
D. Spillan, A.M., M.D., Ed.

5. They say, that the festival of the lupercal, as now celebrated, was even at that time solemnized on the Palatine hill, which, from Palanteum, a city of Arcadia, was first called Palatium, and afterwards Mount Palatine. [2] There they say that Evander, who belonged to the tribe of Arcadians,¹ that for many years before had possessed that country, appointed the observance of a feast, introduced from Arcadia, in such manner, that young men ran about naked in sport and wantonness, doing honour to Pan Lycaeus, whom the Romans afterwards called Inuus. [3] That the robbers, through rage at the loss of their booty, having lain in wait for them whilst intent on this sport, as the festival was now well known, whilst Romulus vigorously defended himself, took Remus prisoner; that they delivered him up, when taken, to king Amulius, accusing him with the utmost effrontery. [4] They principally alleged it as a charge against them, that they had made incursions upon Numitor's lands, and plundered them in a hostile manner, having assembled a band of young men for the purpose. [5] Upon this Remus was delivered to Numitor to be punished. Now, from the very first, Faustulus had entertained hopes that the boys whom he was bringing up were of the blood royal; for he both knew that the children had been exposed by the king's orders, and that the time at which he had taken them up agreed exactly with that period: but he had been unwilling that the matter, as not being yet ripe for discovery, should be disclosed, till either a fit opportunity or necessity should arise. [6] Necessity came first; accordingly, compelled by fear, he discovers the whole affair to Romulus. By accident also, whilst he had Remus in custody, and had heard that the brothers were twins, on comparing their age, and observing their turn of mind entirely free from servility, the recollection of his grand-children struck Numitor; and on making [p. 10]inquiries² he arrived at the same conclusion, so that he was well nigh recognising Remus. [7] Thus a plot is concerted for the king on all sides. Romulus, not accompanied by a body of young men, (for he was unequal to open force,) but having commanded the shepherds to come to the palace by different roads at a fixed time, forces his way to the king; and Remus, with another party from Numitor's house, assists his brother, and so they kill the king.