The Strategic Jewel of the Western Mediterranean

When war broke out in September 1939, Gibraltar's importance to the Allied cause was immediately clear. The Rock commanded the entrance to the Mediterranean — a 14km-wide chokepoint between Europe and Africa through which all naval and merchant traffic between the Atlantic and the Mediterranean must pass. Whoever controlled Gibraltar controlled the western gateway to the inland sea.

For six years, Gibraltar served as one of the most vital — and most threatened — Allied bases in the entire war. It was bombed by Vichy French aircraft, threatened by Franco's Spain, spied upon by German agents from across the border, and honeycombed with over 50km of tunnels carved by hand from solid limestone to house an entire garrison underground.

It never fell. And in helping it not fall, the soldiers, engineers, and civilian population of Gibraltar played a role in the Allied victory that is rarely given the credit it deserves.

The Evacuation of Gibraltar's Civilians (1940)

In May 1940, as the German Blitzkrieg swept through France and the threat to Gibraltar intensified, the British government ordered the evacuation of Gibraltar's entire civilian population — some 16,700 people. It was one of the largest forced evacuations in British colonial history.

Gibraltarians were initially sent to Morocco, then to Madeira, then to London and the UK mainland. Some were evacuated to Jamaica. Families were split, possessions left behind, and the duration of absence stretched from weeks into years — many were not able to return until 1944 or later. For those sent to Britain, the wartime experience was compounded by the Blitz, rationing, and a cold northern climate utterly unlike Gibraltar.

The evacuation — and the community's determination to return — is one of the foundational events of modern Gibraltarian identity. The Gibraltar Museum has a powerful exhibition documenting the evacuation in photographs, personal testimonies, and artefacts.

Digging the Tunnels: The Miracle of Underground Gibraltar

Before the war, Gibraltar already had tunnels — notably the Great Siege Tunnels carved during the 1779–1783 Great Siege by British and Hanoverian troops. But the WWII tunnel network dwarfed anything that had come before.

Beginning in 1939, Canadian, British, and Gibraltarian engineers began the extraordinary task of boring through solid limestone to create an underground city capable of housing the entire garrison — and more. At its peak, the WWII tunnel network extended for over 50 kilometres, with chambers large enough to hold hospitals, ammunition stores, bakeries, power stations, and barracks.

The work was done with pneumatic drills, explosives, and extraordinary manual labour. Thousands of tons of rock were excavated and used as landfill to extend Gibraltar's runway into the bay. The tunnels were built to withstand sustained bombing — and they were never seriously threatened by air attack.

Today, a section of the WWII tunnels — the WWII Tunnel Experience — is open to the public and offers one of the most atmospheric and moving heritage experiences in Gibraltar. Mannequins, original equipment, sound effects and contemporary accounts bring the underground world to life.

Operation Torch: Gibraltar as the Nerve Centre of Allied Landings

In November 1942, Gibraltar played a pivotal and largely secret role in one of the most decisive operations of the war: Operation Torch — the Allied invasion of North Africa.

The Rock served as the command headquarters for the operation, with General Dwight D. Eisenhower establishing his HQ in the tunnels beneath the Rock. From Gibraltar, Eisenhower coordinated the largest amphibious operation in history to that point — over 100,000 Allied troops landing simultaneously on the coasts of Morocco and Algeria.

The decision to base Torch's command in Gibraltar was strategic: the Rock's tunnel network offered protection from bombing, its position at the entrance to the Mediterranean placed it at the operational centre of the theatre, and its communications infrastructure (much of it also tunnelled) was among the most advanced of any Allied base.

The success of Operation Torch was the beginning of the end for Axis power in North Africa. Within six months, all of North Africa was in Allied hands, opening the path to the invasion of Sicily and Italy. Gibraltar's contribution to this outcome was crucial.

Franco's Spain and the Threat Next Door

Throughout the war, Gibraltar faced a threat not just from Germany and Italy but from its immediate neighbour: Spain. General Francisco Franco, who had won the Spanish Civil War with German and Italian support, maintained an official policy of neutrality but was broadly sympathetic to the Axis powers.

Hitler pressed Franco to allow German forces to cross Spain and attack Gibraltar. The famous meeting between Hitler and Franco at Hendaye in October 1940 was partly dedicated to this objective. Franco refused — partly because his price (the French colonies in North Africa) was too high for Hitler to meet, partly because his war-ravaged country was in no condition to sustain another conflict.

Had Spain entered the war on the Axis side and Gibraltar fallen, the entire Mediterranean would have been open to Axis naval domination. The convoys supplying Malta and the Middle East would have been untenable. The Allied ability to project power into the Mediterranean basin would have been severely compromised.

The fact that Gibraltar held — and that Spain stayed neutral — was one of the pivotal contingencies of the war.

German Espionage From La Línea

Even in neutral Spain, Gibraltar was under constant surveillance. German intelligence (the Abwehr) established an observation post in La Línea de la Concepción — the Spanish town immediately adjacent to the Gibraltar border — and employed local agents to monitor shipping movements through the Strait.

Every convoy, every warship, every troop movement that passed through the Strait of Gibraltar was potentially observed and reported to Berlin. British counter-intelligence (MI5 and MI6) mounted extensive operations to compromise or turn these agents — many of whom became double agents feeding disinformation back to Germany.

The Gibraltar border region during WWII was one of the most intense intelligence battlegrounds in the entire conflict — a largely untold story that would make for a remarkable spy thriller.

Visiting Gibraltar's WWII Heritage Today

Gibraltar preserves its WWII heritage better than almost anywhere in Britain. Key sites include:

• WWII Tunnel Experience — within the Upper Rock Nature Reserve. Immersive guided experience through the wartime tunnels. Included in the Upper Rock Nature Reserve ticket.
• Great Siege Tunnels — adjacent to the WWII tunnels. The 18th-century military tunnels that preceded them, with original cannons still in position.
• American War Memorial — on Line Wall Road. Commemorates the American forces who served in Gibraltar and used the Rock as a base for Operation Torch.
• Gibraltar Museum — Bomb House Lane. The evacuation exhibition is particularly moving. Open daily (closed Sundays).
• Commonwealth War Graves — North Front Cemetery contains the graves of those who died in Gibraltar's service during both world wars.

For all attraction details and opening times, see our Things To Do guide and our Historical Sites section.