Soviet invasion of Poland

A long time ago, a big fight began.

First, one group moved into Poland from the west. Then, a second group moved in from the east. This was a very sad and unfair time.

Many people lost their homes. Some people were even taken far away. The two groups split the land between them. It was a very hard time for the people living there. They had to be very brave.

In 1939, a big war began in Europe.

First, Nazi Germany invaded Poland from the west. On 17 September 1939, the Soviet Union invaded from the east. This happened because of a secret deal. The two powers had signed the Molotov–Ribbentrop Pact. This pact divided Poland into two parts. The Soviet Red Army had many more soldiers than the Polish defenders. They moved quickly to take control. Many Polish soldiers were taken as prisoners of war.

After the invasion, life changed for many people. The Soviet government took over the land. They arrested many leaders, like police and priests. They also sent hundreds of thousands of people far away to Siberia. This lasted for several years. Later, Germany took the land from the Soviets. In 1944, the Red Army came back to take it again. After the war, new borders were made between Poland and the Soviet Union. These borders stayed mostly the same for a long time.

In 1939, a major conflict changed the map of Europe. This event is known as the Soviet invasion of Poland. It happened during the start of World War II. First, Nazi Germany attacked Poland from the west. Then, the Soviet Union attacked from the east. This second attack began on 17 September 1939. The two powers worked together to divide the country. This division is sometimes called the Fourth Partition of Poland.

The invasion was planned through a secret deal. This deal was part of the Molotov–Ribbentrop Pact. Two leaders, Adolf Hitler and Joseph Stalin, signed this pact on 23 August 1939. It included a secret protocol about dividing Eastern Europe. The pact created "spheres of influence" for both sides. This meant they agreed on which lands each side would control. Germany and the Soviet Union agreed to divide Poland between them.

The Soviet Red Army moved quickly into Polish territory. They had a much larger number of soldiers than the Polish defenders. Because of this, they met only limited resistance. Some Polish cities, like Dubno and Łuck, let the army in peacefully. These cities thought the soldiers were allies coming to help. However, the Red Army was there to take control. About 320,000 Polish soldiers were taken as prisoners of war.

Life became very difficult for people in the new Soviet areas. The Soviet government began a campaign of mass persecution. They arrested many important people, such as police and priests. The NKVD was a secret police group that used terror. They sent hundreds of thousands of people to remote places like Siberia. This happened in four major waves between 1939 and 1941. Many Polish citizens became Soviet subjects after special elections were held.

The borders of Poland changed many times during the war. Germany occupied the land from the Soviets in the summer of 1941. This happened during an event called Operation Barbarossa. Later, the Red Army returned to take the land back in 1944. After the war, leaders met at the Yalta Conference. They made new agreements about where the borders should be. In August 1945, a new border agreement was finally signed.

The Soviet invasion of Poland was a major military conflict in 1939. It occurred without a formal declaration of war from the Soviet Union. This event took place during the early stages of World War II. Nazi Germany had already invaded Poland from the west sixteen days earlier. On 17 September 1939, the Soviet Red Army began its own invasion from the east. This two-sided attack resulted in the division and annexation of the Second Polish Republic. Historians sometimes refer to this event as the Fourth Partition of Poland.

The invasion was made possible by a secret agreement between two major powers. In August 1939, leaders from Nazi Germany and the Soviet Union signed the Molotov–Ribbentrop Pact. While the public pact was a non-aggression treaty, it contained a secret protocol. This protocol divided Northern and Eastern Europe into "spheres of influence." This meant Germany and the Soviet Union had agreed on which lands each would control. The plan specifically included the partition of Poland between the two nations.

When the Red Army moved into the Kresy regions, the Polish defense was already struggling. The Soviet forces vastly outnumbered the Polish defenders. Because of this massive difference in strength, the Red Army encountered only limited resistance. In some cities, such as Dubno, Łuck, and Włodzimierz Wołyński, the Red Army was even allowed in peacefully. Some local leaders believed the Soviets were arriving as allies to help fight Germany. However, the Soviet Union intended to take control of these territories for itself.

The Soviet occupation brought immediate and severe changes for the Polish people. The Soviet government began a campaign of mass persecution in the newly acquired areas. The NKVD, which was the Soviet secret police, used terror to maintain control. They conducted show elections to make the occupation appear legal to the world. Following these elections, about 13.5 million Polish citizens became Soviet subjects. The Soviet authorities also targeted Polish figures of authority, including military officers, police, and priests.

Repression continued through large-scale deportations and political violence. Between 1939 and 1941, the NKVD organized four major waves of deportation. During these waves, hundreds of thousands of people were sent to Siberia and other remote parts of the Soviet Union. Additionally, many Polish soldiers were captured, with some 320,000 becoming prisoners of war. The Soviet occupation of eastern Poland lasted until the summer of 1941. At that time, Germany ended its pact with the Soviet Union and launched Operation Barbarossa.

The borders of this region shifted several times due to the ongoing war. After Germany invaded the Soviet Union, they occupied the eastern Polish lands. The Red Army eventually reconquered these areas in the summer of 1944. After the war, international leaders met at the Yalta Conference to discuss the future of Europe. They agreed that the Soviet Union could annex territories near the Curzon Line. These lands were added to the Ukrainian, Byelorussian, and Lithuanian Soviet Socialist Republics.

Final borders were established through diplomatic agreements after the war ended. In August 1945, the Soviet Union signed a border agreement with the Polish Provisional Government of National Unity. This agreement recognized the new official borders between the two countries. Most of the territory remained under Soviet control, though some areas were later returned. These included the region around Białystok and parts of Galicia east of the San River. This concluded the long period of territorial change that began with the 1939 invasion.