Babi Yar or Babyn Yar is a ravine in the Ukrainian capital Kyiv and a site of massacres carried out by Nazi Germany's forces during its campaign against the Soviet Union in World War II. The first and best documented of the massacres took place on 29–30 September 1941, killing some 33,771 Jews. The decision to murder all the Jews in Kyiv was made by the military governor Generalmajor Kurt Eberhard, the Police Commander for Army Group South, SS-Obergruppenführer Friedrich Jeckeln, and the Einsatzgruppe C Commander Otto Rasch. Sonderkommando 4a as the sub-unit of Einsatzgruppe C, along with the aid of the SD and Order Police battalions with the Ukrainian Auxiliary Police backed by the Wehrmacht, carried out the orders. Sonderkommando 4a and the 45th Battalion of the German Order Police conducted the shootings. Servicemen of the 303rd Battalion of the German Order Police at this time guarded the outer perimeter of the execution site.