The 'Raid on Twin Pimples' was a British commando raid on a feature in the Italian lines during the Axis 'Siege of Tobruk' in the Western Desert (17/18 July 1941).

The raid was carried out by men of the No. 8 (Guards) Commando and a small number of Australian under the command of Captain M. Keely, and was a complete success. It did not end the siege, however, and this continued until November 1941, when the Allied advance during 'Crusader' reached the town.

During 1941, the British 'Layforce' special forces unit was tasked to carry out a campaign of harassment and dislocation against the Axis forces in the Mediterranean theatre. At the time that 'Layforce' was raised under the command of Lieutenant Colonel R. E. Laycock, the British were in the ascendency as they had largely defeated the Italians, and it was believed that the commandos could be employed in the proposed capture of the Italian-occupied island of Rhodes. However, the arrival of Generalleutnant Erwin Rommel’s Deutsches Afrika Korps in Cyrenaica during February 1941 and the 'Unterhehmen' and 'Marita' German-led invasions of Yugoslavia and Greece wholly changed the strategic situation, and by the time 'Layforce' arrived in Egypt in March the British situation had become dire. The deployment of forces to Greece meant that the commandos became the only troops in general reserve. As the strategic situation worsened, it became increasingly difficult to employ them in the manner intended, as they were called upon as reinforcements to the rest of the army.

In May 1941 most of 'Layforce' was despatched as reinforcements in the 'Battle of Crete' resulting from the Germans' 'Merkur' airborne and seaborne assault. Almost as soon as the 'Layforce' detachment landed the decision was taken that it could not be employed in an offensive role, and would instead be used to cover the withdrawal route to the south coast, from which the Allied evacuation was being made. The 'Layforce' unit was ill-equipped for this type of operation, as it lacked indirect-fire support weapons such as mortars or artillery, and was therefore armed primarily with rifles and a few Bren light machine guns. By 31 May the evacuation was drawing to a close and the commandos, running short of ammunition, rations and water, fell back toward Sphakia. In the end, most of the commandos were left behind on the island to become prisoners of war. By the end of the operation about 600 of the 800 commandos sent to Crete were listed as killed, missing or wounded, and only 179 of the men got off the island.

Shortly after being evacuated from Crete, a detachment of 75 men from No. 8 (Guards) Commando was sent to Tobruk to assist the Allied forces holding out against the Axis forces besieging the port city. The Twin Pimples was a feature in the Axis lines surrounding Tobruk. It was a defensive strongpoint consisting of two closely-spaced hills which dominated the opposing Allied lines, and at the time of the raid was held by Italian units. The 18^th King Edward’s Own Cavalry, normally part of Brigadier A. A. E. Filose’s Indian 3^rd Motor Brigade, held the line across from the Twin Pimples when it was decided to destroy the Italian position. No. 8 Commando was selected to carry out the operation and for some days before its attack the commandos undertook patrols together with Indian troops to get to know the lay of the land.

The plan called for three officers and 40 men of No. 8 Commando and a small number of Australian engineers (to deal with ammunition dumps and gun emplacements) to cross the Italian forward positions to the road that they used to bring up supplies and then follow the road to the rear of the Twin Pimples and engage the position from behind. The 18^th Cavalry was to carry out a diversionary raid just before the commando assault to divert the defenders' attention. The officer chosen to lead the raid was Keely, and the second and third officers were Captain Dunne and Lieutenant Lewes. On the night of the raid, 17/18 July, half the commandos were armed with Thompson sub-machine guns and the other half with Lee-Enfield rifles. All the men carried hand grenades and every third man wore a groundsheet slung bandoleer fashion to use as a stretcher.

The commandos left their own lines at 23.00 on 17 July and crossed the Italian forward positions and main lines without being detected. On reaching the supply road the men had to take cover and wait as the attack was planned for 01.00 on 18 July. They moved closer to their objective just before to the start of the diversionary attack by the 18^th Cavalry. The diversion was a success, and Italian machine gun fire and flares were directed toward the Indian cavalrymen. The commandos managed to get within 30 yards (27.5 m) of the Twin Pimples before being challenged, which triggered a frontal attack by the commandos. The resulting firefight lasted about four minutes, and the Australian engineers planted explosives on several mortars and an ammunition dump. The planners had estimated that the commandos could spend no longer than 15 minutes in the Italian position before it was engaged by the Italian artillery, and the raiders had moved only about 100 yards (91 m) from the Twin Pimples before the Italian artillery started to come down on their own position.

The cost of the raid to the commandos was five men wounded, of whom one later died of his wounds. No. 8 Commando, together with the rest of 'Layforce', was disbanded soon after this. The operational difficulties that had been exposed, combined with the inability of the high command to make a full acceptance of the commando concept, had served to make them largely ineffective. However, two men of No. 8 Commando, David Stirling and Jock Lewes, would form the Special Air Service by the end of July 1941.