The occupation of Latvia by Nazi Germany was completed on July 10, 1941 by Germany's armed forces. Latvia became a part of Nazi Germany's Reichskommissariat Ostland — the Province General of Latvia (German: Generalbezirk Lettland). Anyone not racially acceptable or who opposed the German occupation, as well as those who had cooperated with the Soviet Union, were killed or sent to concentration camps in accordance with the Nazi Generalplan Ost plan.
Immediately after the establishment of German authority in the beginning of July 1941, the elimination of the Jewish and Roma population began, with major mass killings taking place at Rumbula and elsewhere. The killings were committed by the Einsatzgruppe A, and the Wehrmacht. Latvian collaborators, including the 500–1,500 members of the Arājs Commando (which alone killed around 26,000 Jews) and other Latvian members of the SD, were also involved.
30,000 Jews were shot in the autumn of 1941 with most of the remaining Jewish people being rounded up and put into ghettos. In November and December 1941 the Riga Ghetto became crowded and to make room for the imminent arrival of German Jews, who were being shipped out of the country, all the remaining 30,000 Jews in Riga were taken from the ghetto to the nearby Rumbula Forest and shot.
Germany, Austria and the present-day Czech Republic Jews, now located in the Riga ghetto were put to work and placed on very reduced rations. The Kaiserwald concentration camp was built in 1943 at Mežaparks on the edge of Riga which took most of the inmates from the ghetto. In the camp the inmates were put to work by large German companies. Before the Soviet forces returned, all Jews under 18 or over 30 were shot, with the remainder moved to Stutthof concentration camp.