Timeline of the Holocaust: 1940 - 1942
February 12 - German Jews are sent to concentration camps for the first time.
April 9 - Denmark falls to Germany and is occupied by German troops.
May 10 - Germany invades Holland, Belgium, and France.
May 20 - The most infamous of the concentration camps, Auschwitz, is established.
June 22 - France is forced to surrender to Germany.
September 27 - Japan joins with Germany and Italy in the Axis Powers.
October 2 - The ghetto of Warsaw, Poland, is erected.
November 20-24 - The Axis Powers gain three new members: Hungary, Romania, and Slovakia.
March - Adolf Eichmann is appointed the head of the Gestapo.
April - German troops occupy Greece and Yugoslavia.
June 22 - German forces invade Russia.
June-December - Einsatzgruppen begin orchestrated mass murder of eastern European Jews.
September 1 - Germany orders its native Jews to wear the yellow badge.
September 28-29 - German troops massacre 35,000 Jews at Babi Yar, near Kiev.
October 14 - Mass deportation of Jews to concentration and death camps begins. Birkenau is opened as an extermination camp.
October 2319,000 Jews are massacred in Odessa.
December 7 - The Japanese attack on Pearl Harbor incites the United States to join the Allied Powers, and enter World War II.
January 20 - The Wannsee conference meets, and discusses plans for the "Final Solution of the Jewish Problem."
March 1 - Extermination camps begin using poison gas to asphyxiate Jewish prisoners. Beginning with Sobibor, extermination camps used poisons like carbon monoxide and Zyklon B to facilitate mass murder.
March - Deportations to Auschwitz begin.
June 20 - All Jewish schools are closed.
July 28 - Captives of the Warsaw Ghetto organize into a group of fighters.
Summer - Jews from Holland, Poland, France, Belgium, and Croatia sent to extermination camps. There are several armed revolts in Jewish ghettos.
October 4 - All Jews in German concentration camps scheduled for transfer to Auschwitz.
November - Allied troops land in Africa.
Winter - Norwegian, German, and Greek Jews forced into concentration camps. Jewish partisan resistance groups gather in forests to fight the Nazis.