'Pilgrim' was a British unrealised but definitive early plan to take the Portuguese and Spanish island groups in the Atlantic (July 1941/February 1942).

The invasion plan was developed as a contingency for implementation in the event that the Germans started to support Spain with 'Felix' in the latter’s occupation of Gibraltar, the Azores islands group, the Canary islands group and the Cape Verde islands group. The British feared that such occupation would exercise a material and deleterious effect on Allied access to the Mediterranean and endanger the UK’s shipping lanes to many parts of its empire and dominions. 'Pilgrim' was therefore to be a pre-emptive move to occupy the Canary islands group, a Spanish possession, and thereby prevent any German attempt to seize control of the islands. The German invasion never materialised, so 'Pilgrim' was held in abeyance.

After France’s capitulation to Germany in June 1940, General Alfred Jodl, the chief of the operations staff of the Oberkommando der Wehrmacht, presented Adolf Hitler with the OKW’s strategic plans for continuing the war. This comprised two options: the first was a 'direct attack' on the UK with the objective of the occupation of the British isles, and the second an 'indirect strategy' taking the form of an attack on the British empire, especially on the choke points that made it possible to maintain the sea lanes to its dominions and allies. An Anglo-US agreement, by which the USA was to obtain a leases on a number of British bases in the Atlantic in exchange for 50 World War I-vintage destroyers concerned Hitler, as he expected that either the US or the UK could and possibly would invade and occupy one or more of the Spanish or Portuguese island groups in the Atlantic, and thereby gain bases well sited for the defence of its all-important convoy routes against German warship and U-boat operations.

To counter any such actions, the Oberkommando der Wehrmacht began to plan an occupation of the Canary islands group. The study provided two alternatives: firstly, the peaceful transfer and access to the islands to the UK by Spain, and secondly, resistance to the invasion by the local Spanish garrison. The first alternative was eliminated by the Spanish/German negotiations of September 1940 concerning the entry of Spain into the war, where a German offer of forces to reinforce the island defence was rejected by Spain, insisting that the Spanish garrison had the necessary resources to counter a British attack.

Having been assured that the islands would be defended by Spain, Hitler’s Führerweisung Nr 18 of 12 November 1940, which defined 'Felix', recommended the need first to occupy the Portuguese Azores islands group before conducting any attack on Gibraltar, though this latter remained the primary objective of 'Felix'. The directive recommended the reinforcement of the Canary islands group by Luftwaffe and Kriegsmarine forces. In December 1941 the German high command sent Fregattenkapitän Fritz Krauss, authorised by the Spanish government, to investigate the reinforcement and defensive needs of the islands.

The Canary islands group was poorly protected and had been used as a provisional port for sheltering British survivors from ships sank in the Atlantic. Only two military ships were stationed on the islands, many of the islands' artillery pieces dated from the US/Spanish war of 1898, air defence was vested in 25 obsolete Fiat biplanes, and supplies were frequently moved by camel. Krauss made numerous recommendations related to reinforcement, but in February 1941 the Oberkommando der Kriegsmarine ordered the cancellation of all reinforcements because of the indefinite postponement of Spanish belligerency. After a few months, Germany reviewed its position regarding reinforcements and by 22 May, Hitler had agreed to the delivery of four batteries of artillery to Spain for the reinforcement of the islands' defences. The four batteries of 12 guns were distributed between Gran Canaria and Tenerife.

German reinforcement continued until the summer of 1942 but had not solved the problem of a lack of personnel and matériel in the islands' garrison. A matter of concern to the Germans was the fact that in May and August 1942 the UK conducted two amphibious operations: 'Ironclad' to secure the naval base of Diego Suarez at the northern end of the island of Madagascar on 7 May used forces that had been trained to assault the Port of La Luz of Gran Canaria; and 'Jubilee' against Dieppe on the north-eastern coast of France drew the attention of the Spanish high command and alerted the Spanish and German authorities to the capabilities of the British in landing and taking the Canary islands group. By the end of September 1942, there were 34,000 troops on the islands, of which one-third were of North African descent.

On 18 April 1941 the US government announced a line of demarcation between the eastern and western hemispheres, drawn along the 26° W meridian. This became a virtual sea frontier of the USA in the Atlantic and included both Greenland and the Azores islands group. Although not a belligerent, the USA deployed warships to patrol this area and keep the UK informed about any Axis activity, but would not provide any direct protection for British convoys, which thus remained a British responsibility. Both the British and US naval leaderships were concerned about the Azores islands group and suspected that Germany was planning to seize the islands in order to establish U-boat and air basing facilities. German possession and use of such bases in the central part of the North Atlantic posed a major threat to the UK, so the UK and USA started to devlop a plan for an operation to occupy the Azores islands group as well as the Canary and Cape Verde island groups should the Germans move into Spain in support of General Francisco Franco y Bahamonde’s Falangist government and threaten both Gibraltar and these Atlantic island groups.

Gibraltar was essential to the British war effort and Prime Minister Winston Churchill reiterated this by writing that 'Spain held the key to all British enterprises in the Mediterranean.' The very real possibility of losing Gibraltar forced the British government to make contingency plans addressing this risk. Churchill further wrote that 'If we are forced from Gibraltar, we must take the Canaries immediately, allowing us to control the western entry to the Mediterranean.'

The operation to occupy the Canary islands group was initially known as 'Puma', (i) but this evolved into 'Pilgrim' as time and threats progressed and planning changed with the amalgamation of three earlier independent invasion plans: 'Thruster' (i) was the initial plan for the occupation of the Azores islands group; 'Springboard' was the initial plan for the occupation of the Portuguese island of Madeira; and '[Puma' (i) was the initial plan for the occupation of the Spanish Canary islands group and Portuguese Cape Verde islands group.

On 12 March 1941, the Joint Planning Staff signed a document titled J. P. (41) 202 (E) CAPTURE OF THE CANARY ISLANDS, which took the form of a strategic study on the defence of maritime communications and the review of existing plans should Spain either resist or co-operate with the Axis, as well as the advantages of capturing the islands. The operational order for 'Pilgrim' was signed on 20 September 1941.

The object of 'Pilgrim' was to 'capture and hold, for our own use, the Island of Gran Canary with the Harbour at La Luz and aerodrome at Gando'. The invasion was to be led by Major General V. W. Odium’s Canadian 2^nd Division, which was in the UK undergoing training, plus a detachment of Special Operations Executive personnel. (As time passed, the assigned Canadian forces completed their training and were deployed elsewhere, their role in 'Pilgrim' being reassigned to a Royal Marines division supported by the 29^th Brigade.) The total force amounted to about 24,000 men and was to be escorted by Rear Admiral L. H. K. Hamilton’s naval force of one battleship, four fleet carriers, three cruisers and 27 destroyers, plus support vessels of the Royal Fleet Auxiliary: during the planning period and until the cancellation of the operation in February 1942, five different Royal Fleet Auxiliary vessels were placed on alert to participate in the operation, these including Abbeydale, Denbydale, Dewdale, Ennerdale and Olwen. The initial troops assigned for the landings were to be transported by the troop transport Queen Emma. The entire force was to be supported by two squadrons of RAF fighters.

A submarine was to be stationed close to Gando before to the operation’s start to carry out reconnaissance and to act as a navigation aid to the ships if the Spanish coastal navigation lights had been turned off or damaged.

'Pilgrim' was to begin with a nocturnal approach and landing at first light at Puerto de la Luz, the main port on Gran Canaria, by two Canadian infantry battalions from landing craft with air support provided by Royal Navy aircraft from an aircraft carrier and naval gunfire support from the warships. Once the coastal batteries had been silenced, the Canadian forces would enter the Bay of Gando to capture Gran Canaria’s airport at Gando with the help of additional troops via a second landing in the Bay of Ariñaga, and the airport would then be used as the base for a further attack on Tenerife. The 30-strong force of Special Operation Executive operatives was trained to parachute onto Tenerife and conduct sabotage operations to facilitate the British invasion of the island.

The men and landing craft for the operation were kept under orders for the last six months of 1941. The operational plan was simplified after the Allies learned that in the event of any German'''' invasion of the Iberian peninsula, the Portuguese government would evacuate itself to the Azores islands group and would then call on British or US forces to protect the islands.

In 1942 Franco declared Spain’s status as neutral (a change from the previous status of non-belligerent) and the Allies agreed to respect this status. This meant that Germany was deprived of any access to Gibraltar and the Kriegsmarine was denied U-boat or other berthing rights in the Canary islands group. 'Pilgrim' was cancelled in February 1942, and this made possible the assignment of more useful commitments for the landing craft and a re-prioritisation of the naval forces.