Even Encyclopedia Brittanica doesn't have a clue. Having no history is better then twisted history!!!

The European style of presenting wild cat acts was developed by the Hagenbecks in Germany near the end of the 19th century and was soon followed by most trainers in Europe. This style of training uses the natural abilities of the animals and presents them as obedient, even playful pets in harmony with their trainer, rather than in opposition. The wild character of the animals, however, is revealed just often enough to remind the spectator that what was seen was indeed the result of skillful training. Beginning in the late 20th century, in both Britain and the United States, circus owners were often challenged by activists who believed that cruelty was involved in the training of circus animals and who consequently agitated to have such acts banned. Many circuses responded to such charges by pointing out that the days of training animals through punishment (à la Beatty) were long gone; instead, the humane techniques of such trainers as Gunther Gebel-Williams, a German trainer who became famous with the Ringling Bros. and Barnum & Bailey Circus, had become the norm.