The train station in the little French seaside town of Hendaye will forever be guaranteed an ignominious little footnote in the annals of history.

For it was there, on 23 October 1940 – 80 years ago today – that two of Europe’s most feared dictators, General Francisco Franco and Adolf Hitler, met up to discuss the possibility of fascist Spain joining the Axis powers of Germany and Italy in their war against Britain – a meeting of which Spaniards should forever be ashamed.

If Nazi Germany and the Soviet Union – political polar opposites – had been able to hammer out a deal a year earlier (August 1939) resulting in the carving up of Poland, you would have thought that two like-minded dictators would have been able to thrash out an agreement easily enough. Hitler’s Condor Legion had even played a pivotal role in helping Franco win the Spanish Civil War a few years earlier.

The Wehrmacht might have won the Battle of France and conquered the Low Counties, Denmark and Norway but the Luftwaffe’s attempts to bomb the United Kingdom into submission in the summer of 1940 had not gone according to plan, and by October it was clear that the RAF was winning the Battle of Britain.

Just about everything that could go wrong did go wrong during the two men’s seven hours of talks

So, it was perhaps no surprise that Hitler – who in the early years of the war often displayed considerable strategic military nous – was desperate to get his hands on Gibraltar, Britain’s military fortress and naval base on the southern coast of Spain, which commanded the Strait of Gibraltar. (Old photographs showing the pre-war naval dockyard dotted with Royal Navy warships give an idea of its strategic importance.) The Nazi leader believed that seizing the promontory, dominated by the Rock of Gibraltar, which had withstood a string of sieges, held the key to Britain’s defeat. His generals had even drawn up a detailed plan of attack, Operation Felix.

The historian Hugh Trevor-Roper readily admitted that the consequences of a German invasion of Gibraltar would have been catastrophic for Britain, saying: “The Axis would have obtained control of the whole Mediterranean, cut off the British Army in the Middle East and closed a whole future theatre of war. What hope of ultimate victory could even Churchill have then held out?”

In short, the seizure of Gibraltar could have changed the outcome of the war… and possibly have resulted in a Nazi victory.

However, there was just one caveat if Operation Felix – which involved two German army corps, an SS division and a Luftwaffe corps launching an assault on the heavily-fortified Rock – was to succeed: it was dependent on Spanish goodwill and Franco allowing the free passage of German troops to southern Spain. That was one of the issues that Hitler hoped to resolve at Hendaye.

Thankfully for Britain and the future of Western democracy, just about everything that could go wrong did go wrong during the two men’s seven hours of talks.

Firstly, the squeaky-voiced Spanish dictator’s train arrived late, confirming latent German suspicions about the unreliability of their potential new allies.

The seizure of Gibraltar could have changed the outcome of the war

Secondly, Franco made a series of what Hitler thought unreasonable demands: the handing over of Gibraltar to Spain once Britain was beaten; the cession of French Morocco and part of French Algeria, and the attachment of French Cameroon to the Spanish colony of Guinea. Furthermore, the Caudillo (the Spanish equivalent of Fuhrer, a term by which Franco liked to be known) asked for German supplies of food, petrol, and arms to relieve the economic and social hardship in Spain following the civil war.

Such demands would have clearly upset the collaborationist Vichy regime in France, something Hitler wanted to avoid – so the only concrete result of the Hendaye meeting was the signing of a largely meaningless secret agreement by which Franco committed to entering the war at an unspecified future date of his own choosing.

The meeting also left a bad taste in Hitler’s mouth, at least: a few days later he famously told Mussolini that he “would rather have four of my teeth pulled out than deal with that man [Franco] again”.

Further meetings later that year between German and Spanish officials led nowhere, Hitler in his wisdom would soon turn his eyes east to the Soviet Union (Operation Barbarossa was launched in June 1941), and the idea of a German-Spanish alliance was quietly dropped. Meanwhile Spain officially remained “neutral”, though it was a strange kind of neutrality.

After the defeat of Nazi Germany in 1945, Spain’s fascist regime peddled the idea that Franco had been stringing Hitler along the entire time at Hendaye and never really wanted an alliance. However, the distinguished historian Paul Preston argues that the idea that the Caudillo somehow “hookwinked” the Nazi leader “is a central myth of fascist propaganda”. He also points out how Spain refuelled and supplied U-boats, and provided radar, air reconnaissance and espionage facilities for the Nazi regime for much of the war.

Thankfully Spain is now a democracy and has largely banished the ghosts of its fascist past. However, today is a good day to remember the company that Spain’s leaders once kept and be grateful for the fact that the Hendaye meeting remains nothing more than a mere footnote in history.