Carnival began in the 19th Century just 6 weeks before Easter and prior to the period of fasting or Lent begins. Before giving up drinking, Christians wanted to "live it up" one last time before lent season began which is how the tradition of Carnival came to be.
Carnival began as a celebration by The Greeks and Romans to honor the rising spring and driving out the evil from the winter. Christinas adopted these traditions as a celebration around the Lent period and it is often looked at as a "purge" before the fasting season arrises. The costumes came about in the earlier times as a way for the people to hide from church members while out drinking and celebrating. This is one of the most sacred traditions in Germany to this day.
