Schutzhund started at the beginning of this century as a test for working dogs. Its initial purpose was to determine which dogs could be used for breeding and which had true working ability. The growing demand for working dogs made more sophisticated tests and training necessary. These dogs were needed for police training, border patrol, customs, military and herding. As these tests evolved, more people participated just for the sheer enjoyment of seeing if their personal dogs could be trained as effectively as these "professional dogs". Now, over sixty years after the first formal Schutzhund rules were introduced, tens of thousands of people participate in the sport each year.