This article is about the Roman winter solstice festival. There is also an article on the early sauropodomorph dinosaur, Saturnalia.

Saturnalia (from the god Saturn) was the name the Romans gave to their holiday marking the Winter Solstice. Over the years, it expanded to a whole week, the 17th through 23rd of December. It also degenerated from mostly tomfoolery, marked chiefly by having masters and slaves switch places, to sometimes debauchery, so that among Christians the (lower case) word "saturnalia" came to mean "orgy".

It was traditional for Romans to exchange gifts during this holiday. These gifts were customarily made of silver, although nearly anything could be given as a gift for the occasion. Several epigrams by the poet Martial survive, seemingly crafted as riddling gift-tags for gifts of food.

The customary greeting for the occasion is "Io, Saturnalia!" — io (pronounced "yo") being a Latin interjection related to "ho" (as in "Ho, praise to Saturn").

It has been postulated that Christians in the fourth century assigned December 25th as Christ's birthday (and thus Christmas) because pagans already observed this day as a holiday. This would sidestep the problem of eliminating an already popular holiday while Christianizing the population. It created other problems because of the coexistence of the two feasts: see Bishop Asterius of Amasea's New Year's sermon in AD 400, discussed at the entry Lord of Misrule. The medieval celebration of the Feast of Fools was another continuation of Saturnalia into the Christian era.

Seneca the younger wrote about Rome during Saturnalia around AD 50:

It is now the month of December, when the greatest part of the city is in a bustle. Loose reins are given to public dissipation; everywhere you may hear the sound of great preparations, as if there were some real difference between the days devoted to Saturn and those for transacting business....Were you here, I would willingly confer with you as to the plan of our conduct; whether we should eve in our usual way, or, to avoid singularity, both take a better supper and throw off the toga. — From Epistulae morales ad Lucilium

See also

• The Pagan Beliefs Surrounding Christmas