The cavorting Sodales Luperci performed an annual purification of the city in the month for purification -- February. Since early in Roman history March was the start of the New Year, the period of February was a time to get rid of the old and prepare for the new.
There were two stages to the events of the Lupercalia: (1) The first was at the site where the twins Romulus and Remus were said to have been found being suckled by the she-wolf. This is the Lupercal. There priests sacrificed a goat and a dog whose blood they smeared on the foreheads of the young men who would soon go prancing naked around the Palatine (or sacred way) -- aka the Luperci. The hide of the sacrificial animals was but into strips for use as lashes by the Luperci after the necessary feasts and drinking. (2) Following the feast, the second stage began, with the Luperci running around naked, joking, and hitting women with their goatskin thongs.
Naked or scantily-clad festival celebrants, the Luperci probably ran about the area of the Palatine settlement.
Cicero [Phil. 2.34, 43; 3.5; 13.15] is indignant at a nudus, unctus, ebrius 'naked, oiled, drunk' Antony serving as Lupercus. We don't know why the Luperci were naked. Plutarch says it was for speed.
While running, the Luperci struck those men or women they encountered with goatskin thongs (or perhaps a lagobolon 'throwing stick' in the early years) following the opening event: a sacrifice of goat or goat and dog. If the Luperci, in their run, circled the Palatine Hill, it would have been impossible for Caesar, who was at the rostra, to have witnessed the entire proceedings from one spot. He could, however, have seen the climax. The naked Luperci started at the Lupercal, ran (wherever they ran, Palatine Hill or elsewhere), and ended at the Comitium.
The running of the Luperci was a spectacle. Wiseman says Varro called the Luperci 'actors' (ludii). The first stone theater in Rome was to have overlooked the Lupercal. There is even a reference in Lactantius to the Luperci wearing dramatic masks.
Speculation abounds as to the reason for the striking with the thongs or lagobola. Perhaps the Luperci struck men and women to sever any deadly influence they were under, as Michaels suggests. That they might be under such an influence has to do with the fact that one of the festivals to honor the dead, the Parentalia, occurred at about the same time.
If the act was to ensure fertility, it could be that the striking of the women was to represent penetration. Wiseman says that obviously the husbands wouldn't have wanted the Luperci actually copulating with their wives, but symbolic penetration, broken skin, made by a piece of a fertility symbol (goat), could be effective.
Striking women is thought to have been a fertility measure, but there was also a decided sexual component. The women may have bared their backs to the thongs from the festival's inception. According to Wiseman (citing Suet. Aug.), after 276 B.C., young married women (matronae) were encouraged to bare their bodies. Augustus ruled out beardless young men from serving as Luperci because of their irresistibility, even though they were probably no longer naked. Some classical writers refer to the Luperci as wearing goatskin loincloths by the 1st century B.C.
Goats and the Lupercalia
Goats are symbols of sexuality and fertility. Amalthea's goat horn brimming with milk became the cornucopia. One of the most lascivious of the gods was Pan/Faunus, represented as having horns and a caprine bottom half. Ovid (through whom we are chiefly familiar with the events of the Lupercalia) names him as the god of the Lupercalia. Before the run, the Luperci priests performed their sacrifices of goats or goats and dog, which Plutarch calls the enemy of the wolf. This leads to another of the problems scholars discuss, the fact that the flamen dialis was present at the Lupercalia (Ovid Fasti 2. 267-452) in the time of Augustus. This priest of Jupiter was forbidden to touch a dog or goat and may have been forbidden even to look at a dog. Holleman suggests that Augustus added the presence of the flamen dialis to a ceremony at which he had earlier been absent. Another Augustan innovation may have been the goatskin on previously naked Luperci, which would have been part of an attempt to make the ceremony decent.
By the second century A.D. some of the elements of sexuality had been removed from the Lupercalia. Fully dressed matrons stretched out their hands to be whipped. Later, the representations show women humiliated by flagellation at the hands of men fully dressed and no longer running about. (See Wiseman.) Self-flagellation was part of the rites of Cybele on the 'day of blood' dies sanguinis (March 16). Roman flagellation could be fatal. Horace (Sat., I, iii) writes about horribile flagellum, but the whip so used may have been a rougher sort. Scourging became a common practice in the monastic communities. It would seem likely, and I think Wiseman agrees (p. 17), that with the early church's attitudes towards women and mortification of the flesh, Lupercalia fit right in despite its association with a pagan deity.