Why is Kaliningrad part of Russia?

At the Potsdam Conference in 1945 the Allies agreed to transfer the German city of Königsberg and the area around it to the Soviet Union. It became part of the Russian republic of the USSR, was renamed Kaliningrad in 1946, and stayed with Russia when the USSR broke up in 1991.

What was Kaliningrad called before?

Königsberg. It was founded in 1255 by the Teutonic Knights and was the capital of East Prussia.

Why is Kaliningrad separated from the rest of Russia?

When Lithuania became independent in 1991, the Kaliningrad region was left cut off from the rest of Russia, with Poland to the south and Lithuania to the north and east.

Who was Kaliningrad named after?

Mikhail Kalinin, the Soviet Union's nominal head of state, who died in June 1946. The city was renamed on 4 July 1946.

Why is Kaliningrad Russian?

On the map it looks like a mistake: a piece of Russia sitting on its own between Poland and Lithuania, hundreds of kilometres from the rest of the country. For almost 700 years it was a German city called Königsberg.

A Timeless Tales story · 4 minute read

The 60-second version, from my channel. Watch it on YouTube.

A castle for a Bohemian king

The city began in 1255, when the Teutonic Knights, a German crusading order, built a castle on the Baltic coast during their war against the Old Prussians, the pagan people who lived there. They named it Königsberg, "the King's Mountain", in honour of King Ottokar II of Bohemia, who had marched with them.

Königsberg grew into the capital of the Duchy of Prussia and then of East Prussia. In 1701 the Elector of Brandenburg crowned himself the first King in Prussia there. The philosopher Immanuel Kant was born in the city in 1724 and hardly ever left it. Its seven bridges even gave mathematics a famous puzzle: in 1736 Leonhard Euler proved you cannot cross all seven exactly once, and graph theory was born.

1945: the city falls

By the Second World War, Königsberg was a German city of well over 300,000 people. British bombers wrecked its old centre in August 1944, and the Soviet Red Army stormed it in April 1945 after a brutal siege.

That summer, at the Potsdam Conference, the victorious Allies agreed "in principle" that Königsberg and the land around it would go to the Soviet Union. Most of the rest of East Prussia went to Poland. Stalin wanted the region for itself, not least for an ice-free port on the Baltic.

A new name and new people

On 4 July 1946 the city was renamed Kaliningrad, after Mikhail Kalinin, the Soviet Union's nominal head of state, who had died a month earlier. The Germans who had survived the war were deported to Germany by the end of the 1940s, and families from across the Soviet Union were moved in to replace them. Street names, churches and the language all changed. Within a few years almost nobody living there had been born there.

Kaliningrad was made part of the Russian republic of the USSR, not Lithuania, which bordered it. Inside the Soviet Union, that looked like an administrative detail.

1991: cut off

Then the Soviet Union broke apart. When Lithuania became independent in 1991, the Kaliningrad region was suddenly an exclave: Russian territory with no land connection to Russia, bordered by Poland and Lithuania, both of which later joined the European Union and NATO.

Russia kept it. The region is home to Russia's Baltic Fleet, and in the 1990 treaty that reunited Germany, Germany accepted its eastern borders as final, with no claim on its old eastern lands.

1255 Teutonic Knights found Königsberg
1701 First Prussian king crowned there
April 1945 Red Army takes the city
1945 Potsdam: transfer to the USSR agreed
4 July 1946 Renamed Kaliningrad
1991 Lithuania's independence makes it an exclave

Sources

Königsberg, Wikipedia
The Potsdam Conference, 1945, US Department of State, Office of the Historian
Kaliningrad, Wikipedia