Hollywood will never make a film about them, but Sir Oswald Mosley and Diana Mitford formed one of the greatest romantic duos of the 20th century.

The tale of Oswald and Diana's half-century-long love affair featured virtually everything that makes Hollywood salivate – wealth, aristocracy, beauty, charm, war, danger, glamour, betrayal, violence, tragedy, courage, imprisonment and, of course, forbidden love.

But no epic novel or screenplay could possibly match the extraordinary lives of this blessed and doomed couple.

Oswald Mosley is one of the most hated figures in modern British history (in fact, a poll by BBC a few years ago labeled him as the “worst Briton “of the 20th century). Likewise, Diana, who began her life with much promise, and privilege, will also remain a widely detested figure.

The Mosleys were Fascists and Nazi sympathizers, even imprisoned for their beliefs and largely discarded by the establishment that spawned them.

Born to minor aristocracy, the supremely handsome, dashing and mustachioed Mosley fought bravely in World War I (seeing action during the Second Battle of Ypres) and ultimately gravitated toward post-war politics. Initially a member of the Conservative Party, he bristled against its restrictions, and switched over to Labour, before finally embracing the Fascists during the 1930s economic depression that battered the Western world.

Despite devoting his early political career to alleviating the suffering of Britain's poor and unemployed, seeking to avoid another devastating war, and earning raves as a charismatic speaker, Mosley will forever be remembered for forming the British Union of Fascists (inspired by Benito Mussolini's Blackshirts in Italy) and for supporting Adolf Hitler’s rise to power in Germany.

Mosley's personal life was also extremely colorful – he married Lady Cynthia "Cimmie" Curzon, the daughter of the famed former viceroy of India, in May 1920.

Their wedding (which Lord Curzon apparently disapproved of) was the social event of the year, attracting the cream of British aristocracy, including none other than King George V and Queen Mary.

But Mosley was not the monogamous type – not only did he enjoy sexual dalliances with Cimmie's younger sister, Lady Alexandra Metcalfe, but even with his wife's stepmother, Grace Curzon.

After Cimmie died unexpectedly of peritonitis in 1933, Mosley married the love of his life (the woman who was already living openly as his mistress), Diana Mitford.

Diana, regarded by some admirers as the most beautiful woman of her era, was one of the celebrated Mitford sisters, later to be immortalized in various biographies and novels.

Indeed, to be with Mosley, Diana left her first husband, Bryan Walter Guinness, heir to the famous Irish beer fortune, one of the wealthiest men in Europe, perhaps the world.

As if to solidify their mutual attachment to Fascism, Mosley and Diana married secretly in 1936 at the Berlin residence of Josef Goebbels, the Nazi propaganda minister. Der Fuhrer, Adolf Hitler, attended the ceremony as an honored guest.

By this point, Mosley had already mapped out a Fascist future for Britain, greatly impressed by the economic advancements he witnessed first-hand in Nazi Germany and Mussolini's Italy.

“Mosley thought the Italians had developed a form of state that would point to the future and that events in Germany were leading where Britain would follow,” said Matthew Worley, professor of modern history at the University of Reading in the UK.

“He did build a paramilitary force designed to win the streets, come democracy’s fall and the onset of class war. These were modeled on both the Blackshirts and the German [Sturmabteilung] SA.”

With Diana's support and encouragement, Mosley devoted himself to the BUF, delivering speeches, conducting radio broadcasts and raising funds. At its peak, the anti-Communist, pro-protectionist BUF boasted some 50,000 members.

While the BUF attracted some short-term support from “respectable” establishment entities like the Daily Mail newspaper and some Conservative politicians, the Blackshirts' repeated public brawls with Communists, and particularly Jews, across London alienated many.

Any hopes for the BUF rising to mainstream acceptance were permanently dashed in June 1934 at the Olympia in London, when a rally by Mosley deteriorated into a huge brawl that echoed the Nazi violence in Germany.

Perhaps the most notorious incident of public fisticuffs involving the BUF erupted in October 1936, when a march led by Mosley in the heavily Jewish East End of London sparked a massive riot – an event that came to be known as the "Battle of Cable Street."

“The Battle of Cable Street was a kind of turning point because as a result the government banned the wearing of uniforms by non-UK military groups, thereby [forcing] the BUF [to] parade in street clothes and look ridiculous --  a very clever step,” said William Rubinstein, an American-born historian and author who currently works at Aberystwyth University in Wales.

“It was also famous because it was one of the few times in Europe in the 1930s when the extreme right openly ‘fought’ the left, and the left won. It also showed the apparent power of a broadly-based anti-Fascist ‘popular front’ on the left.”

In the next few years, as Britain hurtled itself inevitably into war against Germany, Mosley continued to organize marches while advocating for peace with the Nazis.

By May 1940, eight months into the war, Mosley was imprisoned – Diana would soon join him in internment -- as grave security risks to the nation.

Mosley, Diana and their son Max spent much of the war in Holloway Prison in north London or under house arrest. Bizarrely, they led a relatively normal existence while incarcerated – indeed, owing to their high-born status, they enjoyed such perks as servants, fine food and visitors.

The public viewed them as traitors, though their social circle and family campaigned for their release, Worley noted.

“Winston Churchill was reputedly pleased once they were placed under house arrest rather than held in prison,” he added.

After the war, in the wake of the defeat of Nazism and Fascism in Europe, the Mosleys had no future in British politics, although Oswald continued to call for a "union movement" to unite all of Western Europe under one flag.

By 1951, the Mosleys relocated to Ireland, then later moved to France, where they would spend the rest of their lives.

But in the late 1950s, a new phenomenon emerged in Britain that provided the far right with a new cause to attract renewed support.

What began as a trickle in 1945 led to a significant increase of immigrants from the far-flung corners of the former British Empire, particularly from India, Pakistan and Jamaica.

White Britons across the ideological spectrum grew alarmed at the sudden mushrooming of non-white communities in some of their large cities.

In the wake of race riots in Notting Hill, North London, in 1958, Mosley decided to run in the general election for Kensington North the following year. He lost, but continued to campaign against further Commonwealth immigration, mostly in debates, speeches and television appearances.

Mosley died of natural causes in December 1980 in Paris, at the age of 84, a largely despised figure in the United Kingdom.

Throughout all of Mosley's triumphs, failures and humiliations, Diana remained steadfastly loyal to her husband and his extreme right-wing ideology, speaking lovingly of him until her own death in Paris in 2003.

Nonetheless, Mosley, even in his advancing years, continued to cheat on her. (Ellen Wilkinson, a Labour MP, once described Mosley as a “real-life Valentino.”)

Among Diana's famous sisters, only Unity (a die-hard Nazi who shot herself when Britain declared war on Germany) shared her Fascist beliefs, while her other siblings generally could not abide Mosley. Indeed, for the rest of her life, Diana's relationship with her family grew strained, or nonexistent.

While in Paris, she wrote articles, book reviews, translated French and German manuscripts into English, and published an autobiography in the late 1970s. Still, she never relinquished her attachment to Nazism nor to her cherished memories of Mosley.

What is Oswald Mosley’s legacy to contemporary Britain?

Rubinstein contends that Mosley is not a forgotten figure. Despite his censure by the British government, Mosley remains a far-better remembered figure from the interwar years than even Prime Ministers like Andrew Bonar Law and Ramsay MacDonald.  

Moreover, Mosley’s principal cause of his later years – uncontrolled immigration – remains a dominant theme in UK politics in the early 21st century.

Indeed, the BUF may be viewed as a kind of antecedent to the better-known anti-immigration parties of modern Britain, the National Front, which peaked in popularity in the 1970s until Prime Minister Margaret Thatcher co-opted their message; and the British National Party, which exists today.

Rubinstein notes that, like the BUF, the NF and BNP have never enjoyed mainstream popularity. And by lacking a charismatic leader like Mosley, the BNP may be even less of a political force than the BUF was during its brief heyday in the 1930s.

Indeed, the NF and BNP have been led by non-telegenic, uncharismatic leaders like Nick Griffin, Colin Jordan and Martin Webster, hardly the polished aristocrat that Mosley was.

Mosley also differed from the later quasi-Fascists in another fundamental way.

“Mosley was centrally concerned with unifying the British Empire and making it an autocratic geo-political unit,” Rubinstein noted. “There is no Empire today, obviously, and the BNP, et al., detest the EU.”

Worley noted that the Fascism of the NF and BNP more closely matches the even more overtly racist National Socialist ideas of Mosley’s rival Arnold Leese, who established the Imperial Fascist League in 1928 and was committed to a far more racial concept of Fascism than Mosley.

It is also interesting to compare Mosley with Enoch Powell, the Conservative MP who became the establishment’s face of anti-immigration sentiment during the 1960s. Powell is perhaps most famous for the “Rivers of Blood” speech from April 1968, in which he warned that unrestricted immigration into Britain would spark massive civil unrest.

Worley explains that Powell has a higher profile than Mosley because Powell’s notoriety is more recent and he expressed his warnings of racial conflict during a period when they had some resonance.

“Second, [Powell] was a member of the Conservative Party and therefore very much part of the political mainstream. By the time Mosley moved to Fascism and adopted anti-Semitism he was already an outcast. As a result, Powell’s comments could be contained within the existing political framework, they chimed with ongoing debate and concerns within sections of society at the time, and he was feted within parts of the media.”

It remains unclear how deeply Mosley embraced the most objectionable aspects of Fascist and Nazi ideologies, namely the racial views underlying these philosophies.

Worley indicated that Mosley first viewed Fascism as a more convenient way in which to enact radical economic policies to alleviate the economic crises of the 1920 and 1930s.

“[Mosley also] thought Fascism a more unifying [form of] politics than Communism, which he saw as divisive (i.e., promoting class war) and prone to widescale disruption and bloodshed (as in Russia). The notion of a corporate state and an insulated trading bloc (first the British Empire and then Europe) formed the basis of his politics.”

But once Mosley dove deeply into Fascism, there was no way for him to revert to the mainstream.
“The rise of Hitler and the power of Mussolini enthralled him and he swam in their wake,” Worley declared.

“That said, much of his politics remained constant throughout his life, but the methods by which they should be enacted changed. Was he anti-Semitic and racist? Yes, he was. Did he condone political violence? Yes, he did. “

With respect to Mosley’s alleged anti-Semitism, Rubinstein points out some interesting details.

In 1929-30, he notes, Mosley worked with Emanuel Shinwell, the British trade union official and Labour MP, who was Jewish.

“They worked without incident and must have had many friends among wealthy and acculturated Jews, like anyone from his class and background in the UK,” Rubinstein said.

Even more remarkable, during the early days of the BUF, Mosley’s personal bodyguard was none other than the Jewish boxer, Kid Lewis, born Gershon Mendeloff.

“When Lewis learned that Mosley had become anti-Semitic, he beat him up,” Rubinstein remarked.

Regardless, Mosley likely viewed himself as a potential “British Fuehrer,” but given the vast differences between Britain and Germany or Italy, it was simply not to be.

Yet Mosley, with the radiant Diana standing loyally by his side, remain a fascinating, if dark and troubling, slice of 20th century history that many people appear to have forgotten.

Mosley had five children, the two most prominent being Nicholas (by his first wife, Cimmie) who became a novelist; and Max (by Diana), who rose to some notoriety as the president of the Fédération Internationale de l'Automobile racing organization.