From Wikipedia.com
QuoteThe Lupercalia was an annual [A title="Ancient Rome" href="http://en.wikipedia.org/wiki/Ancient_Rome"]Roman[/A] festival held on [A title="February 15" href="http://en.wikipedia.org/wiki/February_15"]February 15[/A] to honour [A title=Faunus href="http://en.wikipedia.org/wiki/Faunus"]Faunus[/A], god of fertility and forests. [A title="Justin Martyr" href="http://en.wikipedia.org/wiki/Justin_Martyr"]Justin Martyr[/A] identified Faunus as Lupercus, 'the one who wards off the [A title=Wolf href="http://en.wikipedia.org/wiki/Wolf"]wolf[/A]', but his identification is not supported by any earlier classical sources. The festival was celebrated near the cave of [A title=Lupercal href="http://en.wikipedia.org/wiki/Lupercal"]Lupercal[/A] on the [A title="Palatine Hill" href="http://en.wikipedia.org/wiki/Palatine_Hill"]Palatine[/A] (one of the seven [A title="Roman hills" href="http://en.wikipedia.org/wiki/Roman_hills"]Roman hills[/A]), to expiate and purify new life in the [A title="Spring (season)" href="http://en.wikipedia.org/wiki/Spring_%28season%29"]Spring[/A]. This festival's origins are older than the [A title="Founding of Rome" href="http://en.wikipedia.org/wiki/Founding_of_Rome"]founding of Rome[/A].
The religious ceremonies were directed by the Luperci, the "brothers of the wolf", priests of Faunus, dressed only in a goatskin. During Lupercalia, a dog and two male goats were [A title=Sacrifice href="http://en.wikipedia.org/wiki/Sacrifice"]sacrificed[/A]. Two [A title=Patrician href="http://en.wikipedia.org/wiki/Patrician"]patrician[/A] youths were anointed with the blood, which was wiped off with [A title=Wool href="http://en.wikipedia.org/wiki/Wool"]wool[/A] soaked in [A title=Milk href="http://en.wikipedia.org/wiki/Milk"]milk[/A], after which they were expected to smile and laugh. The Luperci afterwards dressed themselves in the skins of the sacrificed goats, in imitation of Lupercus, and ran round the Palatine Hill with thongs cut from the skins in their hands. These were called Februa. Girls would line up on their route to receive lashes from these whips. This was supposed to ensure fertility. The name of the month of [A title=February href="http://en.wikipedia.org/wiki/February"]February[/A] is derived from the Latin februare, "to purify" (meant as one of the effects of fever, which has the same linguistic root).
Quite frankly it's a much better holiday than chocolates and cheap cardboard greeting cards... IMHO