Rommel ordered his panzer divisions south to force Eighth Army to retreat. Montgomery, warned of the impending attack by ultra intercepts, reinforced around Medenine and defended in depth. On 6 March, Rommel attacked on a wide front, his advance spearheaded by the 10th, 15th, and 21st Panzer Divisions, but Montgomery's defense forced Rommel against the strengthened center of Eighth Army.
His offensive halted by antitank fire, Rommel renewed his attacks, which were repulsed with costly panzer losses. Because of his deteriorating physical and mental condition, Rommel departed for Germany on 9 March, leaving command of Army Group Afrika to Generaloberst (U.S. equiv. full general) Hans Jürgen Dieter von Arnim.
Montgomery now went on the offensive, ordering XXX Corps to advance directly against the Mareth Line. Its task was to create a gap that would allow the armor of X Corps to advance through the Gabes gap along the coast toward Sfax and eventually Tunis. Montgomery also ordered the New Zealand Corps wide around the west flank of the Mareth Line. This column swung west and then north in an attempt to break through at the Tebaga gap and reach the El Hamma Plain and envelop Army Group Afrika.
On the night of 20 March, 50th Division launched the main frontal assault on the Mareth Line. A foothold established on the morning of 21 March was lost the next day to counterattacks by the 15th Panzer Division. Meanwhile, on the evening of 20 March, the New Zealand Corps reached Tebaga gap, which forced von Arnim to shift the 164th Light Division and eventually 21st Panzer to meet this threat to his flank.
Montgomery now improvised his original plan and ordered 1st Armoured Division to follow the path of the New Zealand Corps to the Tebaga gap, while the 4th Indian Division took a shorter swing left around the Mareth Line. On 26 March, Montgomery's forces breached the Tebaga gap and threatened the continuity of the German defenses. Von Arnim temporarily saved his deteriorating situation by creating a defensive line at El Hamma. When the 4th Indian Division turned the Mareth Line, von Arnim disengaged the bulk of his forces on 27 March, escaping the envelopment.
In the battle, Montgomery demonstrated his ability to improvise when his initial plan failed, although Army Group Afrika managed to escape his trap. Combined with the successful Operation torch landings, these developments meant the die was now cast for the Axis powers in North Africa. Rommel had predicted that a failure to seize Medenine would be fatal; the collapse of the Mareth Line signaled the beginning of the final chapter in North Africa, which ended with the Allied capture of Tunis on 7 May 1943.
Thomas D. Veve
Howe, George F. Northwest Africa: Seizing the Initiative in the West. Washington, DC: Center of Military History, 1957.; Montgomery, Sir Bernard Law. The Memoirs of Field-Marshal the Viscount Montgomery of Alamein, K. G. Cleveland, OH: World Publishing, 1958.; Rolf, David. The Bloody Road to Tunis: Destruction of the Axis Forces in North Africa, November 1942–May 1943. Mechanicsburg, PA: Stackpole Books, 2001.