Kammala jumla mai zuwa: A ranar 1 ga Satumba, 1939, Jamus ta mamaye Poland, ta fara Yaƙin Duniya na II a Turai, kuma a ranar 17 ga Satumba, bisa ga Yarjejeniyar Molotov-Ribbentrop, Poland ta mamaye Tarayyar Soviet. Daga baya, an sake raba Poland tsakanin waɗannan iko biyu kuma ya kasance a ƙarƙashin ikon Poland.
aiki ga mafi yawan yakin. A ranar 1 ga Oktoba, Jamus da Tarayyar Soviet sun mamaye Poland gaba ɗaya, kodayake gwamnatin Poland ba ta taɓa yin biyayya ba, kuma ba da daɗewa ba aka kafa Jihar Underarƙashin Poland, ƙarƙashin gwamnatin Poland da ke gudun hijira. A ranar 8 ga Oktoba, Nazi Jamus ta haɗu da yankunan yammacin Poland kafin yaƙin kuma, a cikin ragowar yankin da aka mamaye, ta kafa Gwamnatin Janar. Dole ne Tarayyar Soviet ta ba da damar samun nasarar da ta samu a cikin 1939 saboda mamayewar Jamus na Tarayyar Soviet, amma ta sake haɗa yawancin wannan yankin bayan da ta sake cin nasara a tsakiyar 1944. A yayin yakin, Poland ta rasa sama da kashi 20% na yawan mutanen da ke gabanin yakin a cikin wani aiki wanda ya nuna ƙarshen Jamhuriyar Poland ta Biyu.