The first "Oktoberfest" took place on October 12, 1810: For the commemoration of their marriage, Crown Prince Ludwig (later King Ludwig I) and Princess Therese of Saxe-Hildburghausen (namesake of the Theresienwiese festival grounds) organized a great horse race (the marriage took place on October 12th, the horse race on October 17th, therefore there are different dates named as being the first Oktoberfest).
Since 1950, there has been a traditional festival opening: A twelve gun salute and the tapping of the first keg of Oktoberfest beer at 12:00 by the current Mayor of Munich with the cry "O'zapft is!" ("It's tapped!" in the Austro-Bavarian dialect) opens the Oktoberfest. The first mayor to tap the keg was Thomas Wimmer.
By 1960, the Oktoberfest had turned into an enormous world-famous festival. The first Japanese, Americans, and New Zealanders discovered the festival and stumbled with beer mugs alongside Bavarians. They spread the word of Munich worldwide. After this foreigners began to picture Germans as wearing the Sennerhut, Lederhosen, and the girls in Dirndl. Horse races ended in 1960.