In 1255, there's a country of the Holy Roman Empire; and this country belongs to the Teutonic Order, so is Kaliningrad. Kaliningrad was called Koenigsberg(oe is o umlaut) because it also belongs to the HRE. Back in 1701, Koenigsberg was the official capital of Prussia. A few years ago, the Russian Empire barely annexed the city. Nevertheless, they changed the city name to "Kaliningrad" because THEY annexed it while the German variation of "Koenigsberg" was stupid, while Koenigsberg was stupid, racist, foreign and German. Kaliningrad or Koenigsberg was not just a city, but a state. As in the 1750s, the empire fully annexed the state of Kaliningrad; but in the 1910s-30s, one of the Germans from their empire changed the name back to Koenigsberg. In the beginning of the Great Patriotic War, it's USSR's turn to repeat that way they did in their past with the Germans and they changed back into Kaliningrad again. When the Great Patriotic War ends, Kaliningrad belonged to Lithuania and thus, Crimea belonged to Ukraine. While the USSR collapsed in 1991, both Lithuania and Ukraine became independent. then Kaliningrad became the territory of the Russian Federation. Thus for now, Kaliningrad now borders Poland and Lithuania. Poland joined NATO in 1991 and Lithuania did not. Since Poland also joined the EU, Lithuania joined both NATO and the EU aswell. but Kaliningrad was never joined because Russia annexed it; and NATO hated Russia because of the USSR.