Searching for a comparison between "Dionysia" and "Saturnalia," I come across this website, which is upsettingly helpful and clearly went through wonderful magical translation machine. . .
http://www.veselo.info/english/travel/holidays-festivals/carnival/history-carnival.html


History of Carnival Origin
How is wonderful magical holiday come from and where its sources?
Of course, nothing born in an empty place, and no single opinion on these questions.

It is known, that holidays was celebrated in the pre-Christian time and had many common with present carnivals:

* In the Ancient Greece, for instance, in honor of the Dionysus (the god of fructiferous forces of the earth, vegetation, wine-making and the patron of a theatrical act), it was a large religious festival - the Dionysia, which included: merry dances, an execution of joking songs, competitions of poets and awards for victorious actors, and also the masquerade procession, where in front of it always had been the funny “ship” with a costume group. Authors of the Ancient Rome named it “carrus navalis”, what means “sea chariot”.

* In the Rome it was heathen holidays, named the Saturnalia and initiated to the Saturn, god of grain, vegetation and wine. The general idea of the feast consists to invert the ordinary motion of life in time. During two weeks all class boundaries was erased by nonpublic law of festival: the rich and poor was equalized in rights, children headed families, slaves could sit freely with theirs masters at the table and demand from them a subordination, and for reason do not spoil the merriment - everybody hid their faces behind masks. Also, a pseudo-king was chosen at the time of the holiday and in the end of Saturnalias he must be to die by any ways: to be burned, hanged and etc.

After Christianity became popularity, all heathen feasts were forgotten.

* And only thousands years later, in the Venice of Italy, it was created merry and motley holiday, which was celebrated every year before the beginning of the traditional Christian fasting of Lent, at that period Catholics do not eat the meat. And the most probably, the name “Carnival” comes from the Italian «carnovale», which originates from the Latin words “caro” (meat) and “vale” (farewell), literally "Farewell to meat" or from the carnem (meat) + levare (lighten or raise), literally "to remove the meat" or "stop eating meat".