'Addition' was a British special forces raid on the port of Bardia in Cyrenaica (19/20 April 1941).

On 12 April Lieutenant General P. Neame’s Cyrenaica Command had lost Bardia to Generalleutnant Erwin Rommel’s Deutsches Afrika Korps during the latter’s first advance into the north-western region of Egypt after 'Sonnenblume'.

On 12 April Lieutenant General P. Neame’s Cyrenaica Command had lost Bardia to Generalleutnant Erwin Rommel’s Deutsches Afrika Korps during the latter’s first advance into the north-western region of Egypt after 'Sonnenblume'. During March three battalions (or commandos) of Brigadier J. C. Haydon’s Special Service Brigade had arrived in the Middle East theatre on board the three 9,900-ton 'Glen' class cargo-liners adapted as assault landing ships, and a fourth battalion was created from commando forces already in the Middle East.

Comprising men of A Troop from No. 3 Commando, No. 7 Commando, No. 8 (Guards) Commando and No. 11 (Scottish) Commando, with additional personnel provided by No. 50 Commando and No. 52 Commando when they reached Egypt in March, this force for Middle Eastern operations was commanded by Lieutenant Colonel R. E. Laycock, and was therefore known as 'Lay' Force, and its first operation was the 'Addition' seaborne raid carried out by the force’s 500-man A Battalion.

At the time 'Lay' Force came into being, the commando concept was still in its formative stage. As the units of 'Lay' Force left the UK, the original intention had been for the force to be used for a campaign of harassment and dislocation against the German and Italian forces in the Mediterranean theatre. At this time the British were generally superior in the theatre after inflicting a number of significant defeats on the Italians, and it was felt that the commandos could be employed for the seizure of the Italian-held island of Rhodes as part of an expanded 'Cordite'. The arrival of the Deutsches Afrika Korps in Cyrenaica early in 1941 and the invasions of Yugoslavia and Greece on April of the same year then effected a complete alteration of the strategic situation, and by the time 'Lay' Force arrived in Egypt during March the British situation had changed altogether to the worse.

Even so, there was in theory still a role for commando operations. A series of small-scale raids at vital points in the German rear areas, if successful, might have forced Rommel to divert some of his offensive capability to defend his lines of communications. In reality, though, several strategic and operational factors combined to undermined the whole concept for the employment of 'Lay' Force almost from the time of its creation.

Even before the German 'Unternehmen 25' and 'Marita' invasions of Yugoslavia and Greece respectively, a significant proportion of the 8^th Army had been deployed to Greece in operations such as 'Assumption', 'Attendant', 'Barbarity', 'Faggot' (i) and 'Lustre' to strengthen the Greeks fighting off the Italian 'Emergenza G' and to bolster Greek efforts to deter German aggression. 'Lay' Force was not despatched to Greece, though, although the three 'Glen' class infantry assault ships, which had brought the bulk of 'Lay' Force to Egypt and were essential for the effective conduct of amphibious operations, were diverted in an attempt to lessen the lack of British resources in the theatre. This decision essentially robbed the commandos of one of the critical capabilities of their raison d'être, and although Glengyle was later released to Laycock’s force, the other two ships were not and as a result Laycock was severely limited in the forces that he could deploy.

Another major factor was the fact that the British could no longer maintain air superiority in the theatre, which severely limited their ability to undertake amphibious assault operations. Moreover, the deployment of large conventional forces to Greece meant that the commandos became the only troops in general reserve, and that as the British strategic situation worsened it became increasingly difficult to employ them in the manner for which they had been intended as they increasingly became a pool from which reinforcements could be extracted for the rest of the army.

Early in April Laycock was instructed to begin raids on the Axis forces' lines of communication in North Africa: these generally paralleled the coast and only a short distance inland, and were therefore considered vulnerable to amphibious raids. On 12 April 'Lay' Force moved forward to Alexandria, and three days later received orders to raid Bardia and attack Bomba. A and C Battalions were despatched to attack Bardia, while four troops of B Battalion embarked on a destroyer and headed for Bomba. The attacks had to be abandoned as a result of adverse sea conditions, which would have made disembarking and re-embarking too dangerous.

A few days later it was decided to make another attempt on Bardia in 'Addition'. This time the raiders were provided by A Battalion (No. 7 Commando), and embarked in Glengyle. A number of naval support elements were attached, including the British light anti-aircraft cruiser Coventry and the Australian destroyers Stuart, Voyager and Waterhen. Consideration of the German and Italian bomber capability in the theatre decided the British that 'Addition' would be implemented under the cover of darkness, and as a result additional assets in the form of the submarine Triumph and a detachment from the Folbot Troop (later known as the Special Boat Section) under Captain R. J. A. Courtney, were tasked with the provision of navigational assistance by marking both the anchorage and the landing beach.

The operation had been postponed by several days because of rough weather, and the Axis forces had probably been alerted to the possibility of an operation against Bardia by a series of naval bombardments against this and other ports. On the night of 10/11 April the gunboats Aphis and Gnat had shelled Axis transport near Bomba twice and Gazala airfield once, and on the next night six destroyers, covered by the light cruisers Ajax, Orion and Australian Perth, had swept the Cyrenaican coast from Ras Tayones to Ras et Tin. On 13 April the destroyers Stuart and Griffin and the gunboat Gnat had co-operated in Brigadier W. H. E. Gott’s operations against Sollum, and Gnat had suffered some damage from artillery fire. Two days later the light cruiser Gloucester and destroyer Hasty had bombarded transport near Capuzzo and Bardia, and the gunboat Ladybird had shelled Gazala airfield. On 18 April Gloucester had again bombarded vehicles near Bardia, and between that date and the end of the month Ladybird shelled the airfields at Gazala and Bu Amud, while Sollum was again bombarded, this time by Aphis.

Early bombardment had also had the probable effect of persuading the Axis forces not to place great stock in Bardia as a viable forward port.

The raid was carried out on the night of 19/20 April. As a result of a number of mishaps, events deviated from the plan right from the beginning.

When Glengyle arrived off Bardia, one of her LCA assault craft could not be lowered, and there were difficulties releasing the other two. When the assault force finally left the ship, the LCA crews expected to see guiding lights deployed by the Folboat section which was to have arrived slightly earlier, but this had been delayed en route when friendly fire caused its transport, the submarine Triumph to dive and take evasive action. Now somewhat behind schedule, the landing force therefore reached the shore on the wrong beaches. The landings were wholly unopposed, however, and the commandos were able to move to the various targets that had been identified by intelligence. Ultimately, though, little damage was inflicted as a number of the targets proved either to be illusory or were not where they were thought to be. One party was able to damage a bridge, while another set a tyre dump on fire and blew up the breeches of a number of naval guns.

As a consequence of the delays during the landings and the need to depart while it was still dark, time ran out and the commandos were forced to withdraw after achieving little of note. On the way back, an officer was accidentally shot when he failed to respond correctly when challenged by a sentry, while 67 men, not knowing that there were no assault craft at their designated beach as a result of the earlier navigational error, were left behind and later captured.

Despite its limited scope and even more limited tactical success, 'Addition' was nonetheless an operational success inasmuch as the Germans, highly alarmed by the undertaking’s concept and implications, diverted the greater part of an armoured brigade from Sollum, where it was beginning to exert heavy pressure on Lieutenant General N. M. Beresford-Peirse’s Western Desert Force, newly reactivated out of the British XIII Corps, and kept it for some time in this rear area.

The various errors of 'Addition' persuaded the British, however, to end the role of 'Lay' Force as a commando raiding unit and instead use its components as conventional infantry battalions, which was a tasks for which they were neither equipped nor trained. As one of the few reserve forces available, its A and B Battalions were sent to Crete in May 1941 after the Germans had launched their 'Merkur' assault on the island and, fighting as the rearguard, lost 600 men before being evacuated. C Battalion was not sent to Crete but instead to Lebanon, where it lost more than 120 men in the 'Battle of the Litani River' during 'Exporter'. These and other drains on the strength of a force that lay outside the standard replacement system of the British army meant that 'Lay' Force became ineffective as a fighting unit and was disbanded in July 1941.

Many of the men returned to their original regiments following the decision, but others remained in the Middle East and later joined other special forces units that were raised at a later time.