Rubuta ci gaba don wannan sakin layi - Masarautar Prussia ta zama babbar jihar Masarautar Jamus bayan da aka kafa ta a 1871. Koyaya, Yarjejeniyar Versailles bayan Yaƙin Duniya na I ya ba da Yammacin Prussia ga Poland kuma ya sanya Gabashin Prussia wani yanki na Weimar Jamus (sabon Hanyar Poland ya raba Gabashin Prussia daga sauran Jamus), yayin da yankin Memel ya rabu kuma Lithuania ta haɗu da shi a 1923. Bayan nasarar da Nazi Jamus ta yi a Yaƙin Duniya na II a 1945, an raba Gabashin Prussia da yaƙi a kan dagewar Joseph Stalin tsakanin Tarayyar Soviet (Kaliningrad Oblast ya zama wani ɓangare na SFSR na Rasha, da kuma yankunan da ke cikin yankin Klaipėda a cikin Lithuanian SSR) da Jamhuriyar Jama'ar Poland (Warmian-Masurian Voivodeship). An sake sunan babban birnin Königsberg zuwa Kaliningrad a shekara ta 1946. An kwashe yawancin mutanen Jamus da ke lardin.
a lokacin yakin ko fitar da jim kadan bayan haka a cikin fitar da Jamusawa bayan yakin duniya na biyu. Kimanin mutane 300,000 (kusan kashi ɗaya cikin biyar na yawan jama'ar) sun mutu ko dai a cikin hare-haren bam na lokacin yaƙi, a cikin yaƙe-yaƙe don kare lardin, ko kuma ta hanyar zalunci da Red Army.