Crown Prince Ludwig (who later became King Ludwig I), married Princess Therese of Saxony-Hildburghausen on 12th October 1810. The citizens of Munich were invited to attend the festivities held on the fields in front of the city gates, to celebrate the happy royal event. The fields was then named Theresienwiese ("Theresa's fields"), in honor of the Crown Princess. The locals sometimes call it the "Wies'n".

Horse races in the presence of the Royal Family marked the close of the event that was celebrated as a festival for the whole of Bavaria. The decision to repeat the horse races in the subsequent year gave rise to the tradition of the Oktoberfest.

This content is adapted from muenchen.de's "The History of Oktoberfest."