Von Manstein Formulates the Manstein Plan to Invade France After Rejection of Halder Plan
Von Manstein, chief of staff of Army Group A, had originally formulated his plan in October 1939 in Koblenz on instigation of his superior General Gerd von Rundstedt, who rejected Halder's plan, both because of professional jealousy and because it wouldn't lead to a decisive victory over France. Von Manstein's first thoughts were rather traditional, envisaging a swing from Sedan to the north to obliterate the Allied armies in a classical Kesselschlacht or annihilation battle. When discussing his intentions with Lieutenant-General Heinz Guderian, commander of Germany's elite armoured corps, the latter proposed to turn it into a more "Fullerite" strategy by avoiding the main body of the Allied armies and swiftly advancing with the armoured divisions to The Channel instead, to cause a collapse of the enemy by catching him off guard and cutting off his supply lines. It was thus Guderian who introduced the true "Blitzkrieg" elements to the plan, while Von Manstein had at first many objections against this aspect, especially fearing the long open flank created by such an advance. Guderian managed to convince him that the danger of a French counterattack from the south could be averted by a simultaneous secondary spoiling offensive to the south, in the direction of Reims. Guderian before the war had generated much interest for the theories of John Fuller, though never fully endorsing them.
When Von Manstein first presented his ideas to the OKH, he didn't mention Guderian's name and made his classical swing to the north the main effort, while a limited number of armoured divisions protected the left flank of this movement, acting in a classical cavalry strategic reconnaissance rôle. These changes didn't reflect a change of mind on his part, but were thought necessary by him because the original conception was too radical to be acceptable and many conservative generals considered Guderian himself as too radical also. His views were flatly rejected by Halder and Walther von Brauchitsch however. Reformulating them in a more radical sense didn't help and late January Halder managed to remove Von Manstein to the east by having him promoted commander of XXXVIII Army Corps. Von Manstein and Halder were old rivals: in 1938 Von Manstein had been the successor of chief of staff Ludwig Beck but had been removed from this position when the latter fell into disgrace with Hitler because of the Blomberg-Fritsch_Affair. On 1 September 1938 Halder, not Von Manstein, had replaced Beck.
However two officers of Von Manstein's staff, Lieutenant-Colonel Günther Blumentritt Blumentritt and Major Henning von Tresckow, were outraged by Halder's behavior. Late January they contacted Hitler's personal Army attaché, Lieutenant Colonel Rudolf Schmundt (an old acquaintance of von Tresckow) when he was visiting Koblenz, who informed Hitler of the affair on 2 February. Hitler, having found Halder's plans unsatisfactory from the very beginning, ordered on 13 February a change of strategy in accordance with Von Manstein's ideas, even after having only heard a rough outline of them. The general was invited to the Reichskanzlei in Berlin to explain his plans in person to Hitler on 17 February, during a working lunch in the presence of Alfred Jodl and Erwin Rommel. Though Hitler felt an immediate antipathy against Von Manstein, for being too arrogant and aloof, he speechlessly listened to his argumentation, becoming very impressed by Von Manstein's logic. "Certainly an exceptionally clever fellow, with great operational gifts, but I don't trust him", Hitler remarked after Von Manstein had left.
Halder now had to make a fourth main version of the attack plan, Aufmarschanweisung N°4, Fall Gelb. Von Manstein would no further be involved in the planning process, returning to his command of the Army Corps. This new plan conformed to Von Manstein's proposal in this respect that Army Group A would provide the central thrust of the invasion through the Ardennes in southern Belgium. After crossing the Meuse River between Namur and Sedan, Army Group A would then swing northwest towards Amiens, while Army Group B executed a feint attack in the north to lure the Allied armies into the trap. However in many ways the plan was fundamentally changed by Halder. It no longer envisaged a simultaneous secondary attack to the south. Also the "Blitzkrieg" elements were largely removed. The river crossings were to be forced by infantry and there would be a long consolidation phase during which a large number of infantry divisions would be built-up in the bridgeheads. The armoured divisions should then advance in a coherent mass together with the infantry divisions. There would thus not be an independent deep strategic penetration by the German armour.
In 1939, a group of senior German Army officers, including Erich von Manstein and Franz Halder, devised a plan to inflict a major defeat on the French Army in northern France. The Manstein Plan, as it became known, included a attack through southern Belgium that avoided the Maginot Line. The ultimate objective was to reach the Channel coast and to force the French government to surrender.