During World War II itself, German troops crossed the borders into numerous countries, both in Western Europe and in Eastern Europe (not to overlook their North African campaign). Perhaps the most significant border-crossings occurred in September of 1939, when the war began after Germany violated the Polish border, and in June of 1941, when Germany crossed the border of their "ally," the Soviet Union, and thereby ensured their ultimate defeat in the war.
Poland :<
WW2 began when German troops invaded Poland.
German troops crossed through Belgium in an attempt to flank the French forces lined in trenches along the border.
During World War II itself, German troops crossed the borders into numerous countries, both in Western Europe and in Eastern Europe (not to overlook their North African campaign). Perhaps the most significant border-crossings occurred in September of 1939, when the war began after Germany violated the Polish border, and in June of 1941, when Germany crossed the border of their "ally," the Soviet Union, and thereby ensured their ultimate defeat in the war.
Because German troops had crossed the border into Belgium, contravening a longstanding treaty that guaranteed Belgian neutrality.
German troops invaded Poland, so the Polish border.
The army of Nazi Germany crossed the southern border of Estonia on 7 July 1941. Estonian capital, Tallinn, was conquered by German troops on 28 August 1941.
Poland, they stepped over the borders of Poland, triggering a war as Germany has already taken most of Europe at the time and this resulted in thousands of deaths.
Poland
German troops crossed the border into Poland on September 1, 1939, which marked the official start of World War II. This invasion followed the signing of the Molotov-Ribbentrop Pact between Germany and the Soviet Union, allowing for the division of Eastern Europe. The swift military action employed by Germany, known as Blitzkrieg, led to the rapid fall of Poland and triggered declarations of war from Britain and France.
The German army crossed the Danish border on April 9, 1940 by land, sea, and air.
When Germany first tried to invade France they sent troops to the German-France border and the France- Belgium border to fight the incoming of the SS