Following the Invasion of Poland at the beginning of World War II, nearly a quarter of the entire territory of the Second Polish Republic was annexed by Nazi Germany and placed directly under the German civil administration.

[1] The annexation was part of the "fourth partition of Poland" by Nazi Germany and the Soviet Union, outlined months before the invasion, in the Molotov–Ribbentrop Pact.

Already in the fall of 1933 Adolf Hitler revealed to his closest associates his intentions to annex western Poland into an envisioned Greater Germany.

Wartheland was the only Gau constituted solely from annexed territory,[3] Danzig-West Prussia comprised also former German areas and the former Free City of Danzig.

[14] On 3 October 1939, the military districts centered on and named "Lodz" and "Krakau" were set up under command of major generals Gerd von Rundstedt and Wilhelm List, and Hitler appointed Hans Frank and Arthur Seyß-Inquart as civil heads, respectively.

[21] In late 1939 a sixteen-man commission was also active to chart the boundaries of a projected Reichsgau Beskidenland (named after the Beskid mountain range), which would have encompassed the areas lying west of Kraków up to the San river to the east of it.

[22] Nazi Party Secretary Martin Bormann on the other hand proposed that the General Government would in the near future be turned into 3–5 Reichsgaue or Reichsobergaue, including the Galician district.

[23][24] Leaving such discussions open for the conclusion of the war, Hitler never officially adopted or implemented any of these suggestions, instead retaining the status quo of using the areas as a labor reservoir.

[10][25] Due to flights, war losses, natural migration and the lack of contemporary reliable data, demographics especially in the border regions can only be estimated.

[39] On October 7, 1939, Hitler appointed Heinrich Himmler as his settlement commissioner, responsible for all resettlement measures in the Altreich and the annexed territories as well as the Nazi-Soviet population exchanges.

[40] For his new office, Himmler chose the title Reichskommissar für die Festigung deutschen Volkstums ("Reich's commissioner for strengthening Germandom", RKF).

[42] This directive was superseded by another RKF-directive of early 1940,[42] ordering the immediate expulsion of the remaining Jews and the replacement of 3.4 million Poles with Germans settlers in the long run.

[48] The removal of Poles consisted of such actions as ethnic cleansing, mass executions, organised famine and eradication of national groups by scattering them in isolated pockets for labour.

[56] Heinemann and Łuczak as cited by Eberhardt detail the expulsions as follows: 81,000 Poles were displaced from their homes in East Upper Silesia,[32][55] 22,000 of whom were deported to the General Government.

[64] Members of Hitler Youth and the League of German Girls were assigned the task of overseeing such evictions to ensure that the Poles left behind most of their belongings for the use of the settlers.

[66] Anna Bramwell says 591,000 ethnic Germans moved into the annexed territories,[63] and details the areas of colonists' origin as follows: 93,000[63] were from Bessarabia, 21,000[63] from Dobruja, 98,000[63] from Bukovina, 68,000[63] from Volhynia, 58,000[63] from Galicia, 130,000[63] from the Baltic states, 38,000[63] from eastern Poland, 72,000[63] from Sudetenland, and 13,000[63] from Slovenia.

[63] Additionally some 400,000 German officials, technical staff, and clerks were sent to those areas in order to administer them, according to "Atlas Ziem Polski", citing a joint Polish-German scholarly publication on the aspect of population changes during the war.

Because Nazi Germany envisioned a near-term complete Germanization of the annexed territories, measures there differed from those implemented in the General Government.

Doubts about the ability to perform mass sterilization hindered this idea, however, as 55% of available doctors in certain parts of annexed territories were Poles and it was thought they would sabotage the action.

[28] The proposed solution to Polish problem was mass sterilization of lower classes (named "primitives" by the report), sending married Poles to slave labour in Reich.

[28] Stripping Poles of all cultural activity by the Germans and leaving them to spend all time outside of work in homes, led to conditions favourable to sex and a rising birth rate.

[86] Overall the German hierarchy silently accepted (and in some cases supported or encouraged) the discrimination and treatment of Poles as Untermenschen, with notable individual exceptions who either protested or tried to help their fellow church members of non-German ethnicity.

[86] In time, as the war continued, the growing split between German Catholics and the persecuted Polish church facing destruction worried the Vatican and the Pope himself.

Another notable German member of the clergy was archbishop Adolf Bertram who personally contacted the Vatican with the request to Germanise the Catholic Polish church organisation.

[86] The earliest victim was the Pomeranian Voivodeship where almost every Catholic Polish church was closed down, robbed and turned ever into some kind of warehouse, stable or depot.

It was Dymek who through his energetic protests finally started worrying the Vatican that it would eventually lose all of the Polish churches in the region-in no less than 2–3 months.

[91] The harshness of German law was demonstrated by such cases, as 5 months of penal camp for a woman who smiled to English POW's in Ostrów Wielkopolski.

[6] Himmler himself oversaw cases of obstinate Germans, and gave orders for concentration camps, or separation of families, or forced labor, in efforts to break down resistance.

[98] Nazi Germany put the Germans in a position to economically exploit the Polish society, and provided them with privileges and a comparably high standard of living at the expense of the Poles, to ensure their loyalty.

[3] Germans received the right to enter any Polish home at will to perform revision and identification of people living there at any time, and could acquire possessions from Poles and Jews with little effort and mostly without payment or at a low price.