The most well-known commandant of the Auschwitz-Birkenau concentration and extermination camp during World War II was Rudolf Höss. He held the position from May 1940 until November 1943, overseeing the expansion of the camp and the implementation of the mass extermination of Jews using gas chambers. It was during his tenure that Auschwitz became the largest Nazi concentration and extermination camp, resulting in the deaths of over 1 million Jews and hundreds of thousands of other individuals.