SS-Hauptsturmführer Adolf Haas became the first commandant of the Bergen-Belsen camp in the spring of 1943; SS-Hauptsturmführer Josef Kramer replaced him in December 1944. The number of SS functionaries in Bergen-Belsen varied over the course of the camp's existence. The SS succeeded in destroying many of the camp's files, including those on personnel.
Bergen-Belsen [ˈbɛʁɡn̩.bɛlsn̩], or Belsen, was a Nazi concentration camp in what is today Lower Saxony in northern Germany, southwest of the town of Bergen near Celle. Originally established as a prisoner of war camp, in 1943, parts of it became a concentration camp. Initially this was an "exchange camp", where Jewish hostages were held with the intention of exchanging them for German prisoners of war held overseas. The camp was later expanded to accommodate Jews from other concentration camps.