The Birkenstock brand traces its roots to a German by the name of Johann Adam Birkenstock. It was Johann's grandson, Konrad Birkenstock, who developed the first contoured insole to be used by shoemakers in the production of custom footwear. Konrad also developed the first flexible arch support to be inserted in factory-made shoes. In 1964 these inserts were developed further into a shoe by Karl Birkenstock, and what would become the Birkenstock sandal was created.