“At last news hasreached us – the Soviets are already near the forest! Many people have seen them. What had  previously been rumoured had become a fact! From the east, Russian soldiers had entered Poland. In the morning they entered the village. (…) They looked menacing. They scattered around the village and were looking for something or someone. They entered attics, cellars, and stabbed the thatched roofs of barns and houses with bayonets, and we all cowered in fear in the corners”. This is how Ryszard Gaik – author of the book Ufaj, że wrócę [Trust that I will come back] (Wrocław 1992), from which the quoted fragment comes – remembers the beginning of the Soviet occupation in September 1939.

The Soviet Union’s invasion of Poland on 17 September 1939 came as a shock to Polish society. For several days, the country had been defending itself against the German invasion. The eastern borders were guarded only by units of the Border Protection Corps (Korpus Ochrony Pogranicza) – after all, no one expected aggression from that side. Meanwhile, an attack on Poland from the east was also planned on 23 August 1939, when the foreign ministers of Germany and the Soviet Union concluded a non-aggression agreement, the secret part of which provided for a joint attack on Poland (the Molotov-Ribbentrop Pact). Stalin fulfilled his commitment on 17 September, throwing more than 600,000 Red Army troops into the eastern provinces of the Republic. Without declaring war, the Soviets confined themselves to handing a note at 3 a.m. to the Polish ambassador in Moscow, Wacław Grzybowski, stating that since the Polish state had ceased to exist, the Soviet Union was obliged to take the Byelorussian and Ukrainian populations (and these made up a large proportion of the population of the Polish eastern provinces).

The events of mid-September 1939, in a way, determined the fate of several hundred thousand Polish citizens who were deported to Siberia and Kazakhstan in 1940-1941. This is why we celebrate Sybirak’s Day on 17 September, formally established by the Polish Sejm in 2013. Previously, for many years, Sybiraks celebrated their holiday unofficially.

The events of September 1939 (the division of Polish lands between two occupying powers as a result of the aggression of Germany and the Soviet Union) are often referred to as the ‘fourth partition of Poland’.