While the German attack into the Low Countries drew the British Expeditionary Force (BEF) and principal French armies into Belgium, Panzer Group Paul von Kleist quietly moved through the Ardennes with the first units of general of panzer troops Heinz Guderian's XIX Panzer Corps arriving opposite at Sedan on the evening of 12 May. General Charles Huntziger's French Second Army defended the Sedan vicinity, but it was not unduly alarmed by the German arrival.
Preceded by a very accurate and demoralizing five-hour bombing attack of French defensive positions conducted principally by Ju-87 Stuka dive-bombers, on 13 May German infantry and motorcyclists succeeded in crossing the Meuse east and west of Sedan. The French defenders, consisting mostly of new reservists, were surprised by the rapid German river crossing. Despite the lack of reserves and insufficient artillery and air support, the French resisted fiercely, but they were gradually driven back. By the end of 13 May, the Germans had secured a bridgehead 3 miles wide and 6 miles deep. German military engineers worked feverishly to construct pontoon bridges and tank ferries.
The commander of the French 55th Infantry Division at Sedan, Général de Division Henri Jean Lafontaine, remained calm and prepared to continue the fight. Unfortunately, others were not so determined. To the north, General André Georges Corap's French Ninth Army had already retreated, leaving the Second Army's flank exposed. Within the French Second Army, some commanders, believing that the Germans had already penetrated the French positions, ordered their units to retreat. The retreat of these units started a panic within the French forces. Despite this, the French sent two tank battalions and two infantry regiments to counterattack the bridgehead. The French attempted a two-pronged counterattack on 14 May with their 1st, 2nd, and 3rd Armored Divisions, but only the 3rd was able to reach a part of Guderian's forces. The French armored unit lacked the tactical flexibility to mount an effective attack and suffered heavy casualties, not to German armor but to the antitank guns of the German assault engineers. After losing half of their tanks, the French withdrew. Repeated air attacks by French and British bombers throughout the day achieved little and brought heavy air losses for the attackers.
By the end of 14 May, the French defenders were in complete disarray. The French 55th and 71st Infantry Divisions sustained heavy casualties and fled the battlefield, causing panic in the neighboring French X Corps. The German bridgehead was 30 miles wide and 15 miles deep. The Germans also held the key terrain, which denied the French the ability to mount an effective counterattack.
During the course of the battle, the realistic training and combat experience of the German forces proved decisive. German commanders were aggressive and rapidly pursued any advantage they discovered. Their use of combined arms gave them an unmatched tactical flexibility and agility and allowed them to constantly outmaneuver and destroy the French forces piecemeal. By 15 May, Guderian's forces were across the Meuse River in strength and ready to exploit the opening they had punched in the French defenses.
C. J. Horn
Doughty, Robert A. The Breaking Point: Sedan and the Fall of France, 1940. Hamden, CT: Archon Books, 1990.; Guderian, Heinz. Panzer Leader. New York: Ballantine Books, 1987.