'Supercharge II' was the British breakthough of the Tebaga gap in south-eastern Tunisia by Lieutenant General Sir Bernard Freyberg’s New Zealand Corps to complete the 'Pugilist-Gallop' outflanking movement round the southern end of the Mareth Line by General Sir Bernard Montgomery’s British 8^th Army (26/31 March 1943).

The Tebaga gap is a low mountain pass located in rough rocky broken country giving entry to the inhabitable coastal plain to the north and east from much less hospitable desert-dominated terrain of southern and south-western Tunisia. The pass separates the Matmata hills to the east running approximately north/south from the Djebel Tebaga hills, another line of high ground to the west of the gap running east/west. The combined terrain of the region about the pass was of critical importance in the middle stages of the Tunisian campaign.

The original plan devised by Montgomery for the Mareth Line battle had been for Lieutenant General Sir Oliver Leese’s British XXX Corps to make a frontal breakthrough of the Mareth Line defences, which were held by the Italian forces of Generale di Corpo d’Armata Paulo Berardi’s XXI Corpo d’Armata and Generale di Corpo d’Armata Taddeo Orlando’s XX Corpo d’Armata, by which time the New Zealand Corps (Freyberg’s own New Zealand 2^nd Division, Brigadier C. B. C. Harvey’s British 8^th Armoured Brigade and Général de Division Philippe François Marie Jacques Leclerc de Hauteclocque’s Free French Force 'L') would have completed a 120-mile (195-km) flank march to reach and break through the Tebaga gap (held by Generale di Divisione Alberto Mannerini’s Raggruppamento Sahariano) to debouch into the coastal plain of southern Tunisia and so take Gabès, thus cutting the lines of communication to (and also line of retreat for) Generale d’Armata Giovanni Messe’s Axis 1^st Army as it pulled back from the Mareth Line.

'Pugilist-Gallop' failed as such on 22 March when the XXX Corps could not drive through the Mareth Line and the New Zealand Corps could not break through the Tebaga gap in the face of determined counterattacks by Generalmajor Hans Georg Hildebrandt’s 21^st Panzerdivision and Generalmajor Kurt Freiherr von Liebenstein’s 164^th leichte Afrikadivision.

Little deterred by this setback, Montgomery swiftly developed 'Pugilist' into a new 'Supercharge II', in which the Axis forces on the Mareth Line would be pinned by the XXX Corps while Lieutenant General B. G. Horrocks’s X Corps (including Major General R. Briggs’s 1^st Armoured Division) moved as rapidly as possible through Wilder’s Gap in the southern end of the Matmata Hills to reinforce the New Zealand Corps at the Tebaga gap. This wide outflanking movement was covered by an inner flanking movement by Major General F. I. S. Tuker’s Indian 4^th Division, which advanced Brigadier D. R. E. R. Bateman’s Indian 5^th Brigade and Brigadier O. D. T. Lovett’s Indian 7^th Brigade from Medenine through the northern end of the Matmata Hills in an apparent effort to move past the end of the Mareth Line to take Matmata and Toujane.

While the XXX Corps (Major General A. F. Harding’s 7^th Armoured Division, Major General J. S. Nichols’s 50^th Division and Major General D. N. Wimberley’s 51^st Division) continued to exert pressure on the Axis forces in the Mareth Line, on 23 March the Indian 4^th Division and the X Corps started their movement to the south on their separate tasks, which Montgomery planned to unleash simultaneously with an attack on the Mareth Line by the 7^th Armoured Division so that the Germans and Italians (already in dire mobility straits as a result of the efforts of Air Vice Marshal H. Broadhurst’s Western Desert Air Force) would be faced with three widely separated attacks and thus be unable to reinforce any of the potential breakthrough sectors.

However, it was at the Tebaga gap that 'Supercharge II' was expected to yield the greatest results, especially as some 22 squadrons of fighter-bombers were allocated to provide close air support for the attack, scheduled to start at 16.00 on 26 March.

After a preliminary undertaking during the night of 25/26 March to capture Height 184, the New Zealand Corps was to attack into the Tebaga gap on a two-brigade front and capture the Axis defences from Djebel Tebaga to Djebel Melab, which would be exploited by the 1^st Armoured Division. After assembling during the night and lying in concealed positions all day, Brigadier H. K. Kippenberger’s New Zealand 5^th Brigade was to attack on the right and Brigadier W. Gentry’s New Zealand 6^th Brigade on the left, preceded by the 8^th Armoured Brigade and a creeping barrage by the artillery of the New Zealand Corps and X Corps. The New Zealanders were to move to high ground 2,000 yards (1830 m) forward and then to a second objective at a wadi 2,500 yards (2285 m) farther on. The 1^st Armoured Division, led by Brigadier A. F. Fisher’s 2^nd Armoured Brigade, was to move through at 18.15 to an area 3,000 yards (2745 m) beyond the New Zealand Corps' final objective and, as soon as the moon rose at about 23.15, advance on El Hamma.

British bombers were to start a major harassment of the Axis forces during the night of 25/26 March with bomb attacks on transport and communications lasting until 15.30, at which time lighter day bombers would begin low-level pattern bombing designed to add to Axis disorganisation, followed by relays of fighter-bombers every 15 minutes for 150 minutes. Supermarine Spitfire fighters were to escort the bombers and fighter-bombers, and the remainder of Air Marshal Sir Arthur Coningham’s North-West African Tactical Air Force was to bomb Axis airfields. RAF forward observation officers were on hand with the troops to brief pilots by nominating landmarks, marking targets with red and blue smoke, friendly troops using orange smoke, and the artillery firing smoke shells to signal to the aircrews.

On 24 March, Generaloberst Hans-Jürgen von Arnim, commanding the Heeresgruppe 'Afrika', had doubted that an 8^th Army attack was imminent, and was more concerned about the threat to Maknassy farther to the north. Despite the slow pace of the British advance in the south, von Arnim wished the 1^st Army to withdraw to Wadi Akarit on 25 March, but Messe and von Liebenstein preferred to counterattack with the 15^th Panzerdivision. The threat to Maknassy and the possibility that Major General George S. Patton’s US II Corps would penetrate to Gabès, and thereby cut off the 1^st Army, meant that the 1^st Army had to retire from Mareth and then from Tebaga.

Height 184 fell at 02.50 on 26 March to the New Zealand 21^st Battalion, and the Allied artillery began to fire at 04.00. The attack began with the 8^th Armoured Brigade, followed by the infantry in carriers and then on foot, against some two German battalions of the 164^th leichte Afrikadivision on a front of 2,000 yards (1830 m). It appeared that the 164^th leichte Afrikadivision and 21^st Panzerdivision had not expected a daylight assault and were therefore taken by tactical surprise, which was compounded by difficult observation conditions as a result of the setting sun, wind and dust. The British tanks had been ordered to press forward, and the New Zealand infantry also kept up a swift progress as they reached their first objective and then kept going in the face of increasing resistance and delays. An armoured regiment pressed on to Wadi Aisoub beyond the second objective, followed by the New Zealand 23^rd Battalion. On the left, a minefield covered by anti-tank guns was bypassed on both sides as the British and commonwealth forces closed on their second objective, clearing a gap for the 1^st Armoured Division, despite the fact that many Axis posts continued to hold out in the area.

By the fall of night a gap had been driven into the Axis defences. Pausing only until the rising of the moon at about 23.15 provided renewed illumination, the 1^st Armoured Division advanced through the gap and moved swiftly on El Hamma, some 20 miles (32 km) to the north-east, half-way to Gabès on the coast. During the morning of 27 March, the 15^th Panzerdivision was moved forward from reserve to counterattack the New Zealand Corps on its right flank, but by 09.00 the German counterattack had been repulsed and the New Zealand Corps advanced into the hills on its right. By the evening of 27 March, German resistance had been broken and the line of communication forward to the 1^st Armoured Division had been secured, the armoured division having been halted by the defences of El Hamma and then waited for the arrival of moonlight. Freyberg persuaded Horrocks that the New Zealand Corps, en route to El Hamma to link with the 1^st Armoured Division, should branch off to the right to avoid the Axis defences at El Hamma and head across the broken ground direct to Gabès.

By 28 March, all the Axis forces on the Mareth Line had withdrawn to face the X Corps and New Zealand Corps on their right flank but, by checking the 1^st Armoured Division at El Hamma, managed to avoid encirclement. On 29 March, the New Zealand Corps took Gabès, which forced a further Axis withdrawal to a new line 15 miles (24 km) to the rear of Gabès at Wadi Akarit, while the 164^th leichte Afrikadivision, 15^th Panzerdivision and 21^st Panzerdivision fought rearguard actions. The Axis forces fell back from El Hamma on 29 March, leaving the way open for the 1^st Armoured Division to advance to the north with the New Zealand Corps on its right.

On 31 March 'Supercharge II' came to an end. It had cost the 8^th Army 4,000 casualties, many of them from the 50^th Division, and a large number of tanks; the New Zealand Corps lost 945 men and 51 tanks. The New Zealand Corps was now disbanded and its elements were reallocated to the X Corps and XXX Corps.

Although the 1^st Army pulled back in good order to a defensive line at the Wadi Akarit, it had nonetheless lost more than 7,000 men, of whom 2,500 were Germans, taken prisoner. In overall terms, the 1^st Army had suffered the loss of 16 battalions of infantry, 31 pieces of artillery and 60 tanks.