During December of 2010 we tried to Make Sense of Christmas by understanding the history behind many of our traditions. There is much history to learn about Mardis Gras as well:
Historians tell us that the ancient Romans probably kicked off the Mardi Gras celebrations. Their mid-February festival known as Lupercalia honored the god Lupercus, alternately known as the god of fertility and the god of agriculture and pastoral shepherds. In either case, his party definitely had Mardi Gras-like qualities, including days of feasting and drinking. And a little enjoying the “pleasures of the flesh”, probably, too — in fact, the term Carnival, often synonymous with Mardi Gras, is derived from the Latin expression meaning “farewell to the flesh.”
Like most of the ancient Roman and Greek festivals, Lupercalia was adopted and adapted by the Church as a way of subtly converting the local pagans to Christianity. The carnival-like celebration of Lupercalia thus morphed into a last “fling” before the beginning of the Lenten period.