The official origin of Oktoberfest was the wedding of Bavarian Crown Prince Ludwig and Princess Therese of Saxony-Hildburghausen on October 12, 1810. They decided to throw a party for all the commoners to celebrate their union in a meadow outside of Munich, which they named Theresienwiese. The party went on for days and ended with a horse race on October 17. People liked the celebration so much, they decided to make it an annual event. And so the Munich Oktoberfest tradition began.
But that still doesn't explain why the festivities begin in September. Some historical accounts say the celebration, which began to span a couple weeks -- because five days of partying just isn't enough -- was moved to the end of September so they could enjoy better weather.
The German Beer Institute's story of the less formal origins of the festival dates back to the fifteenth century. Back then, the only way to refrigerate beer was to stick it in a dark cellar or a snow-covered cave. Making beer in the summer would result in a funky brew, so Bavarians realized it was better to make it through the fall and winter and then store it. The March beers -- or Märzen -- would have a higher content of hops and alcohol, which would act as a preservative, and be stored for the spring and summer.
When fall was approaching and the grain harvest -- which ended in October -- was almost over, it was time to empty out those kegs for the new brews. So they would have a celebration from the end of September to the beginning of October to drink all the remaining beer. Now, there's a good excuse to get wasted.
With the big wedding celebration in 1812, the festival became an official event, and the beer drinking was justified. Although beer wasn't part of the main event during the first year, it became prominent in the subsequent celebrations, with the addition of beer tents which kept getting bigger.
Today, more than six million people from all around the world flock to Munich to be part of the official Oktoberfest. In this festival, they only serve beer from six Munich breweries. But, since everyone loves beer, the celebration has spread all over the world with all sorts of variations.
Denver's own Oktoberfest parties began last weekend, and the celebrations continue this weekend at the Lowry Beer Garden and many other locations. If you're getting drunk in the name of Oktoberfest, now you know why.