After months of nervous speculation, Germany brought war to western Europe on May 10, 1940, with the primary goal of conquering France. German bombers hit air bases in France, Luxembourg, Belgium, and the Netherlands, destroying large numbers of Allied planes on the ground and crippling Allied air defenses. Elite squads of German paratroopers were dropped onto fortified Allied points along the front, neutralizing a key element of France’s defense strategy.
On the ground, German forces advanced in two directions: one through the Netherlands and northern Belgium (where Britain and France had expected) and the other, larger force to the south, through Luxembourg and into the Ardennes Forest on a path that led directly into the French heartland. Unaware of the German advance to the south, Britain and France sent the bulk of their troops to Belgium.
During the first days of the attack, the Germans made slower progress toward Brussels and The Hague than expected, as the Dutch forces fought back formidably. In response, on May 14, the German air force, the Luftwaffe, unleashed a massive bombing attack on central Rotterdam, even while surrender negotiations with the Netherlands were under way. Although efforts were made to call off the attack at the last minute, only some of the German pilots got the message, so part of the attack was carried out. Over 800 civilians were killed, and the Netherlands surrendered that day.
The British and French plan to defend Belgium was to make a stand at a line of forts between the cities of Antwerp and Liege. Unaware that these forts had already been captured by German paratrooper units on the first night of the invasion, the British and French armies found themselves under assault on May 13. At the same time, the second, unexpected German offensive to the south emerged from the Ardennes Forest. Over the next few days, the main Allied armies were trapped between the two German forces, able neither to protect Paris nor to stop the Germans from advancing to the English Channel. Then, when the German troops to the south moved between the French and British forces, the Allies were divided and thus weakened further still. The Allied defense of Belgium was unequivocally a disaster.
While the main French army was trapped between the two German armies, the British Expeditionary Force (BEF) was being pushed to the coast near the French port of Dunkirk. With the BEF cornered with its back to the sea, and with little hope of reuniting with French forces, the British government decided that the BEF had to be evacuated. The evacuation, called Operation Dynamo, began on May 27, 1940. It took a full week to accomplish, using more than 800 civilian and military sea vessels. In all, more than 300,000 men were brought back across the English Channel to British soil. The feat was heroic—it was done under nearly constant bombardment from the Luftwaffe—but it left France completely on its own.
With the British out of the way, the Germans began their final push against France. By June 12, German tanks had broken through the main fronts along the Somme River and the fortified Maginot Line, moving ever closer to their goal, Paris. During this time, the British vigorously encouraged France to resist at all costs. The new British prime minister, Winston Churchill, even flew to Paris himself to offer his personal encouragement. At the same time, though, the British government denied French requests for military assistance, wanting to conserve strength for Britain’s own defense in the near future.