It all started on 1st September 1939.
At 4:47 a.m. the battleship “Schleswig-Holstein” fired at Westerplatte – the Polish Military Transit Depot in the Free City of Danzig. Seven minutes earlier, German air forces bombarded Wieluń – the town with no military targets. At the same time, Wermacht units were invading the country. Under their onslaught, the Polish Army began to retreat further into the country. Germans introduced their extermination policy on the occupied territories, committing the first crimes on prisoners of war and civilians. Despite an overwhelming prevalence of German forces, the Polish Army was holding out. On 17th September, under the Molotov–Ribbentrop Pact, the Polish eastern border was crossed by the Red Army, stabbing the defending Polish units in the back. The war was lost. The state authorities and survived Polish units were evacuated abroad to Romania in order to continue the fight with the occupiers with the aid of the western allies – France and England.

Following a short battle, Białystok was seized by Germans on 15th September 1939. After a week of German occupation, meeting the provisions of the Molotov–Ribbentrop Pact, the city was surrendered to Soviets. The fourth partition of Poland became a fact.

For the inhabitants, the two-year period of Soviet “public order” began.