Explained: Why is Kaliningrad so important to Russia?

Lithuania on Monday began blocking goods banned under EU anti-Russia sanctions from being transported through its territory to Russian's Kaliningrad exclave. Prohibited items include coal, metals and construction materials. Over the weekend, video footage showed some panic buying at construction supply stores.

Russia's foreign ministry blasted the ban as "openly hostile," with Russian TASS news agency reporting that the transport of food has also been blocked. Moscow warned that Lithuania may face measures of "serious negative impact" in response. Lithuania, however, said it was merely fulfilling its responsibilities as an EU member by implementing sanctions imposed on Russia in response to its invasion of Ukraine.

What is Kaliningrad?

Kaliningrad is Russia's westernmost region, or oblast. It is an exclave, meaning it shares no borders with mainland Russia. Kaliningrad has a strip of Baltic Sea coast in its west, while bordering on Lithuania in the north and east, and Poland in the south. It spans an area of 15,000 square kilometers (5,830 square miles, about the size of East Timor), and has a population of roughly a million. Its capital is the eponymous city of Kaliningrad, where about half of that population lives.

Why does Kaliningrad belong to Russia?

The area of present-day Kaliningrad used to be part of the Kingdom of Prussia, and had a mixed Polish, Lithuanian and German-speaking population. After the defeat of Nazi Germany at the end of World War II, the territory was ceded to Soviet Russia. Its main city, known in German times as Königsberg, was renamed Kaliningrad — the same name given to the entire area.

After the collapse and disintegration of the Soviet Union, Kaliningrad became part of Russia.

Why is Kaliningrad important to Russia?

Kaliningrad's geographic location is strategically and militarily advantageous to Russia. It is Russia's only port on the Baltic Sea that is ice-free year-round, and the Russian Baltic Sea Fleet is based there.

Russia also holds nuclear missiles in Kaliningrad, placing them within close striking range of major European capitals. Neighboring countries Lithuania and Poland are EU and NATO states.

What else in Kaliningrad known for?

Philosopher Immanuel Kant was born in Königsberg, today's city of Kaliningrad, in 1724. He spent most of his life in the Prussian city and lies buried there. Kant is famous for trying to synthesize scientific and moral progress.

Kaliningrad also happens to be the center of the world's amber trade. Some 90 percent of the world's amber reserves are found there.