Reichskommissariat Ostland in the context of "Collaboration with Nazi Germany and Fascist Italy"

The Baltic states—Estonia, Latvia and Lithuania—were occupied and annexed by the Soviet Union in 1940 and remained under its control until its dissolution in 1991. For a period of several years during World War II, Nazi Germany occupied the Baltic states after it invaded the Soviet Union in 1941.

The initial Soviet invasion and occupation of the Baltic states began in June 1940 under the Molotov–Ribbentrop Pact, made between the Soviet Union and Nazi Germany in August 1939, before the outbreak of World War II. The three independent Baltic countries were annexed as constituent Republics of the Soviet Union in August 1940. Most Western countries did not recognise this annexation, and considered it illegal. In July 1941, the occupation of the Baltic states by Nazi Germany took place, just weeks after its invasion of the Soviet Union. The Third Reich incorporated them into its Reichskommissariat Ostland. In 1944, the Soviet Union recaptured most of the Baltic states as a result of the Red Army's Baltic Offensive, trapping the remaining German forces in the Courland Pocket until their formal surrender in May 1945.

The Estonian Soviet Socialist Republic (abbreviated Estonian SSR, Soviet Estonia, or simply Estonia [ˈeˑstʲi] ) was an administrative subunit (union republic) of the former Soviet Union (USSR), covering the occupied and annexed territory of Estonia in 1940–1941 and 1944–1991. The Estonian SSR was nominally established to replace the until then independent Republic of Estonia on 21 July 1940, a month after the 16–17 June 1940 Soviet military invasion and occupation of the country during World War II. After the installation of a Stalinist government which, backed by the occupying Soviet Red Army, declared Estonia a Soviet constituency, the Estonian SSR was subsequently incorporated into the Soviet Union as a union republic on 6 August 1940. Estonia was occupied by Nazi Germany in 1941, and administered as a part of Reichskommissariat Ostland until it was reconquered by the USSR in 1944.

The majority of the world's countries did not recognise the incorporation of Estonia into the Soviet Union de jure and only recognised its Soviet administration de facto or not at all. A number of countries continued to recognise Estonian diplomats and consuls who still functioned in the name of their former government. This policy of non-recognition gave rise to the principle of legal continuity, which held that de jure, Estonia remained an independent state under occupation throughout the period 1940–1991.

The military occupation of Latvia by Nazi Germany was completed on 10 July 1941, by Germany's armed forces. Initially, the territory of Latvia was under the military administration of Army Group North, but on 25 July 1941, Latvia was incorporated as Generalbezirk Lettland, subordinated to Reichskommissariat Ostland, an administrative subdivision of Nazi Germany. Anyone not racially acceptable or who opposed the German occupation, as well as those who had cooperated with the Soviet Union, was killed or sent to concentration camps in accordance with the Nazi Generalplan Ost.

The Reich Ministry for the Occupied Eastern Territories (RMfdbO; German: Reichsministerium für die besetzten Ostgebiete), commonly known as the Ostministerium, (pronounced [ˈɔstminɪsˌteːʁiʊm] ; "Eastern Ministry") was a ministry of Nazi Germany responsible for occupied territories in the Baltic states and Soviet Union from 1941 to 1945. Alfred Rosenbergserved as Reichsminister with Alfred Meyer as his deputy during its existence.

The Ostministerium was created by Adolf Hitler shortly after the German invasion of the Soviet Union to control the vast areas captured and projected for capture by the Wehrmacht in the Baltic states, Belarus, Ukraine, and Russia. Two Reichskommissariats were established: Ostland and Ukraine, while two more were planned, Moskowien and Kaukasien, but the Wehrmacht never established firm possession of the areas designated and German civilian control never developed there. The Ostministerium was involved in the development and implementation of Generalplan Ost, which fell under its jurisdiction, along with the Reich Commission for the Consolidation of German Nationhood, the Reich Security Main Office, and the SS Race and Settlement Main Office. It was one of the main agencies that oversaw the Holocaust in the Soviet Union.

Erich Koch (German: [ˈɛʁɪç kɔx]; 19 June 1896 – 12 November 1986) was a Gauleiter of the Nazi Party (NSDAP) in East Prussia from 1 October 1928 until 1945. Between 1941 and 1945 he was Chief of Civil Administration (Chef der Zivilverwaltung) of Bezirk Bialystok. During this period, he was also the Reichskommissar in Reichskommissariat Ukraine from September 1941 until August 1944 and in Reichskommissariat Ostland from September 1944. After the Second World War, Koch stood trial in Poland and was convicted in 1959 of war crimes and sentenced to death. The sentence was later commuted to life in prison and Koch died of natural causes in his cell at the Barczewo prison on 12 November 1986.

Vileyka Region (Belarusian: Вілейская вобласць, romanized: Viliejskaja voblasc; Russian: Вилейская область, romanized: Vileyskaya oblast) was a territorial entity in the Byelorussian Soviet Socialist Republic created on 4 December 1939 out of the eastern powiats of the Wilno Voivodeship after the Soviet annexation of Western Belorussia of (then part of the Kresy Zachodnie region in Poland) into the Byelorussian SSR on 14 November 1939. The administrative centre of the region was the city of Vileyka.

Initially the region consisted of Vileyka, Ashmyany, Braslaw, Dzisna, Pastavy, and Sventiany districts. In January 1940, it consisted of 22 districts: Astravyets, Ashmyany, Braslaw, Vidzy, Gadutsishki, Hlybokaye, Dzisna, Dokshytsy, Dunilavichy, Ilya, Kryvichy, Kuraniets, Maladzyechna, Miory, Miadzieł, Pastavy, Plisa, Radashkovichy, Smarhon, Sventiany, Svir and Sharkawshchyna. In November 1940, the Gadutsishki and Sventiany districts, as well as parts of the Astravyets, Ashmyany, Pastavy and Svir districts were transferred to the Lithuanian SSR. Also, during the German occupation between 1941 and 1944, Ashmyany District was part of Wilna Land General Bezirk at Litauen and the city of Vileyka Glubokoye was part of General Bezirk Weissruthenien in Reichskommissariat Ostland.

The German invasion of the Soviet Union during World War II started on 22 June 1941 and led to a German military occupation of Byelorussia until it was fully liberated in August 1944 as a result of Operation Bagration. The western parts of Byelorussia became part of the Reichskommissariat Ostland in 1941, and in 1943, the German authorities allowed local collaborators to set up a regional government, the Belarusian Central Rada, that lasted until the Soviets reestablished control over the region. Altogether, more than 2,000,000 people were killed in Belarus during the three years of Nazi occupation, around a quarter of the region's population, or even as high as 3,000,000 killed or 30% of the population, including 500,000 to 550,000 Jews as part of the Holocaust in Belarus, with an estimation that 1 in 3 Belarusians died during WW2. In total, on the territory of modern Belarus, more than 9,200 villages and settlements, and 682,000 buildings were destroyed and burned, with some settlements burned several times. By the end of the war, Belarus had lost half of its population as a result of death and moving, the worst of any European state.

Otto-Heinrich Drechsler (1 April 1895 – 5 May 1945) was a German Nazi politician who served as the General Commissioner of Latvia for the Nazi Germany's occupation regime (Reichskommissariat Ostland) during World War II. In this capacity, he played a role in setting up the Riga ghetto and was implicated in the extermination of Latvian Jews. He committed suicide on 5 May 1945, after being captured by British forces.