Adolph 'Adi' Dassler and his brother Rudolph owned their own shoe company in Germany during the 1920s and 30s. Their products were so popular, many of the German competitors in the 1928 Olympics wore Dassler Brothers shoes.
During WWII the brothers had a falling out. Both joined the Nazi
party, but Rudolph was more fanatical and went off to fight, leaving
Adi to make shoes for the military. After the war ended, Rudolph
left and formed his own company, Puma. Adi then renamed the original
company after himself, and Adidas was born.