Kaliningrad is an oblast in the Northwestern Federal District of the Russian Federation. It's administrative center is the city of Kaliningrad.
In violation of a longstanding treaty in perpetuity, Lithuania cut off rail traffic of critical materials to the Russian federal territory of Kaliningrad. The Russian foreign ministry said: ‘We consider provocative measures of the Lithuanian side which violate Lithuania’s international legal obligations, primarily the 2002 Joint Statement of the Russian Federation and the European Union on transit between the Kaliningrad region and the rest of the Russian Federation, to be openly hostile.’
Modern Kaliningrad consist of the northern half of the former territory of East Prussia, the original heartland of Prussia. It is an area of rich farmland, lakes and forest bordered to the east and south by the Russian Empire and to the west by the Baltic Sea. The main city was Konigsberg (King's City) the former summer retreat of the Kaisers and Prussian monarchs It was also the home of philosopher Immanuel Kant. The region featured very large estates controlled by Junker elites and nobles.
The province was a battleground in 1914-15, when, following the outbreak of the First World War Russian armies invaded the province but were decisively defeated at the Battle of Tannenberg in 1914 and the Battle of the Masurian Lakes. Following Germany's defeat in 1918, the Treaty of Versailles divided Germany and the state of Poland re-created, which included the Polish Corridor to the Baltic Sea and the port city of Danzig (later Gdansk) declared a "Free City", neither part of Germany or Poland. East Prussia remained part of Germany (with the exception of the port of Memel, seized by newly-independent Lithuania). In 1939 Nazi Germany forced Lithuania to relinquish Memel.
After the Second World War, about 9 million Germans were deported to the West, and East Prussia was divided between the Soviet Union and Poland. Memel - renamed Klaipeda - became part of the Soviet Republic of Lithuania; northern East Prussia, with Konigsberg (renamed Kaliningrad), became part of the Russian Federated Republic (known as Kaliningrad Oblast), and the southern part was ceded to Poland. Adolf Hitler's wartime headquarters, Wolfschanze from which he directed Operation Barbarossa, was in the territory ceded to Poland.
Since 1946 Kaliningrad has served as a trip wire in Russian defense strategy against aggression from Western Europe. Kaliningrad, which is separated from Russia proper, in Soviet and post-Soviet times as been described as the largest military base on the planet.
The Memel territory was separated from German East Prussia in 1920, and put under French administration. The area had been conquered by the Teutonic Order in the Middle Ages, and had belonged to Prussia for at least 500 years. It was inhabited by Germans as the largest part of the population, while a quarter declared itself Lithuanian, and another quarter, as local Memelländer and/or Klaipedians depending on language.
In 1923, Lithuanian forces occupied the area during what is called the Klaipeda revolt. The French forces put up a token resistance and left, and later the annexation of the area now called the Klaipeda region by Lithuania was confirmed by the International Community. This was considered a Western betrayal by many, especially by France who did not protect autonomy either with their troops, or by diplomacy. Also, when the government of the Weimar Republic agreed to the annexation in 1928, it was also considered a betrayal by many Germans, by their own government.