[1][2] Einsatzkommandos, along with Sonderkommandos, were responsible for the systematic murder of Jews during the aftermath of Operation Barbarossa, the invasion of the Soviet Union.

Einsatzgruppen (German: special-ops units) were paramilitary groups originally formed in 1938 under the direction of Reinhard Heydrich – Chief of the SD, and Sicherheitspolizei (Security Police; SiPo).

[5][6] Hitler ordered the SD and the Security Police to suppress the threat of native resistance behind the Wehrmacht's fighting front.

Heydrich met with General Eduard Wagner representing Wilhelm Keitel, who agreed to the activation, commitment, command, and jurisdiction of Security Police and SD units in the Wehrmacht's table of operations and equipment (TOE); in the rear operational areas, the Einsatzgruppen were to function in administrative sub-ordination to the field armies in order to effect the tasks assigned them by Heydrich.

Their principal task (during the war), according to SS General Erich von dem Bach, at the Nuremberg Trials: "was the annihilation of the Jews, Gypsies, and Soviet political commissars".

They were a key component in the implementation of the "Final Solution of the Jewish question" (German: Die Endlösung der Judenfrage) in the conquered territories.

[7] When occasion demanded, German Army commanders bolstered the strength of the Einsatzgruppen with their own regular-army troops who assisted in rounding up and murdering Jews of their own accord.

They were composed of the Gestapo, Kripo and SD functionaries, and deployed during the classified Operation Tannenberg (codename for murder of Polish civilians) and the Intelligenzaktion lasting till the spring of 1940; followed by the German AB-Aktion which ended in late 1940.

It included politicians, scholars, actors, intelligentsia, doctors, lawyers, nobility, priests, officers and numerous others – as the means at the disposal of the SS paramilitary death squads aided by Selbstschutz executioners.

It is a tally sheet of the actions of Einsatzkommando 3—a running total of their killings of 136,421 Jews (46,403 men, 55,556 women, 34,464 children), 1,064 Communists, 653 persons with mental disabilities, and 134 others, from 2 July to 1 December 1941.

[2] On 30 June 1941 Himmler visited the newly formed Bezirk Bialystok district and pronounced that more forces were needed in the area, due to potential risks of partisan warfare.

The chase after the Red Army's rapid retreat left behind a security vacuum, which required urgent deployment of additional personnel.

Scrambling to meet the "new threat", Gestapo headquarters in Zichenau (Ciechanów) formed a lesser known unit called Kommando SS Zichenau-Schroettersburg, which departed from the sub-station Schröttersburg (Płock) under the command of SS-Obersturmführer Hermann Schaper, with the mission to murder Jews, communists and the NKVD collaborators across the local villages and towns in the Bezirk.

The relief unit, called Kommando Bialystok,[20] was sent in by SS-Obersturmbannfuhrer Eberhard Schöngarth on orders from the Reich Security Main Office (RSHA), due to reports of Soviet guerrilla activity in the area with Jews being of course immediately suspected of helping them out.

In compliance, Einsatzkommando 8 reached Bialystok on 1 July, passed through Słonim and Baranowicze, and began systematic mass killing operations in modern-day southern Belarus (eastern Poland before World War II).

To the south and east of Smolensk and Minsk, the two Sonderkommandos left a wake of dead civilians, from Velikiye Luki, Kalinin, Orsha, Gomel, Chernigov and Orel, to Kursk.

The Einsatzkommando was active in Lviv (see the Lwów Ghetto), Brody, Dubno, Berdičhev, Skvyra and Kiev (Babi Yar).

The Einsatzkommando was active in Lviv, Zolochiv, Zhytomyr, Proskurov (modern Khmelnytskyi), Vinnytsia, Dnipropetrovsk, Kryvyi Rih, Stalino and Rostov.

[25] The Einsatzgruppe E was deployed in Croatia (i.e. in Yugoslavia) behind the 12th Army (Wehrmacht) in the area of Vinkovci (then Esseg), Sarajevo, Banja Luka, Knin, and Zagreb.

Einsatzkommando Italien was a German paramilitary unit active in Italy, headed by Judenreferent SS-Hauptsturmführer Theodor Dannecker.