The French defeat at Sedan left the Allies in Belgium with sparse flank protection. The limited and relatively meager Allied flank protection that there existed was swiftly, rapidly, and handily defeated by the German forces in their driving and pressing offensive attack-thrust from their breakout at Sedan. The breakout was so fast that there was little fighting. Many French soldiers were taken prisoner before they could offer resistance, which also explains the low number of casualties suffered both sides. The two assault engineer battalions under Korthals achieved the most important success. By eliminating the bunkers in the Bellevue sector, they made the breakthroughs of the 1st and 2nd Panzer Divisions possible and this was achieved without loss. Military historians agree that the Battle at Sedan sealed the fate of Belgium and France. On 14 May, the Allied forces had been wrong-footed and through their failures in deployment forfeited the campaign. The advance to the Channel trapped 1,700,000 soldiers and expelled the Allies from Western Europe. The bulk of the British Army escaped from the port of Dunkirk but the Allies left behind large amounts of equipment. In controversial circumstances, the German armed forces failed to eliminate the British trapped in the pocket. The encirclement destroyed the best units of the French Army, including a prisoner of war total of 40,000 but 139,732 British and 139,037 French troops escaped. French and British forces were dispatched from England and participated in the battles of June 1940, the French surrendering along with the rest of the French armed forces on 25 June 1940, when the Armistice of 22 June took effect.