But the success created new tensions in the brothers’ relationship, already strained by the fact that their families lived in the same villa despite their wives not getting along. There were several incidents that were said to have precipitated their conflict, but the most widely accepted one took place during World War II when the Allies were bombing Herzogenaurach. As Adi and his wife climbed into a bomb shelter already occupied by Rudi and his wife, he exclaimed, “The dirty bastards are back again,” referring to the Allied forces. Rudi was convinced the remark was directed at him and his family. A feud — one of the most epic and, well, Biblical in business history — was born. (Not surprisingly Adidas vs. Puma is No. 20 on Fortune‘s list of the 50 greatest business rivalries of all time.)