The Daily Mail has always been a viciously reactionary newspaper, prepared to slander and malign anyone perceived to be a threat to the interests of its proprietor Viscount Rothermere and his class.

It most famously published the forged Zinoviev Letter in order to damage the Labour Party in 1924, but also went after Stanley Baldwin, the Tory leader, for being a crypto-socialist in 1931.

The Mail routinely praised the achievements of Italian fascism in the 1920s. Mussolini, according to Rothermere, was “the greatest figure of our age”. He had saved Europe from the menace of Communism.

Rothermere wrote in the Mail that it was because Bolshevism was stopped in Italy that “it collapsed in Hungary and ceased to gain adherents in Bavaria and Prussia”. As far as he was concerned, what Britain needed was heroic leadership on the Italian model.

With the rise of Nazism, he found a new hero. The election of September 1930 saw the Nazis dramatically increase their support in the Reichstag, from 12 seats to 107. The Mail published an article, “A Nation Reborn”, enthusiastically celebrating the Nazi success.

A delighted Hitler granted an interview to the Mail’s German correspondent, Rothay Reynolds, telling him how pleased he was that Rothermere could “understand what we have in our hearts”.

Rothermere and Hitler went on to be good friends, meeting on a number of occasions and corresponding regularly. Rothermere gave his new friend a photographic portrait of himself in a solid gold frame.

As far as Rothermere was concerned the Nazis were not only going to save Germany from Communism, but also showed the way forward for Britain. He remained critical of British Tories for being too liberal when what the country needed was a good taste of authoritarian reaction to smash the left once and for all and to restore Britain’s imperial might.

He thought he had found just the man to achieve this objective in Oswald Mosley.

When Mosley first broke with the Labour Party, Rothermere urged him to embrace fascism as the way forward, promising him the full support of his newspaper empire. Mosley founded the British Union of Fascists in October 1932.

Initially, Rothermere withheld his support, but after the Nazis took power in Germany in 1933, with the support of German conservatives, he threw his papers behind the Blackshirts.

On 10 July 1933 Rothermere had celebrated Hitler’s coming to power with an article titled “Youth Triumphant”, written from “somewhere in Naziland”. He urged all young people “to study closely the progress of the Nazi regime” and “not to be misled by the misrepresentations of its opponents” who were trying “to give the impression that Nazi rule is a bloodthirsty tyranny”.

As for the new regime’s murderous antisemitism, it was merely curbing the influence of “alien elements”!

Rothermere’s support for Mosley produced the infamous headline, “Hurrah for the Blackshirts” in the Mail in January 1934, the Sunday Dispatch offer of a £5 prize for a photograph of the most beautiful female Blackshirt, the Evening News competition, “Why I Like the Blackshirts” with a £1 prize for the week’s winner and much more.

Rothermere even invested £70,000 (nearly £3 million in today’s money) in a joint cigarette business venture with the BUF. And at the Mail, staff began turning up for work wearing black shirts in a grovelling display of sympathy for their proprietor’s politics. BUF membership shot up.

Rothermere soon broke with Mosley, though not over any objection to Blackshirt violence or the BUF’s vicious antisemitism as is sometimes suggested.

Rothermere fell out with Mosley because he saw the role of the BUF as being to pull Conservative opinion over to the hard right, whereas Mosley wanted to replace the Conservative Party altogether.

Even after he ended his support for Mosley, Rothermere remained strongly attached to the Nazis. As far as Rothermere was concerned, Hitler was always a “great gentleman”. He praised him in the Mail as “a man of rare culture” whose “knowledge of music, painting and architecture is profound”.

This eulogy appeared soon after the Kristallnacht pogrom of March 1938 that left over 90 Jews dead, every synagogue in Germany wrecked and over 30,000 Jews thrown into concentration camps where hundreds more died.

All this changed overnight once war broke out, with the Mail going from Nazi apologist to ultra-patriotism, a display of hypocrisy that remains very much the paper’s hallmark. As for Rothermere, he was afraid that his private correspondence with Hitler was going to become public and that when it did the public demand for his internment and trial for treason would prove irresistible. Not even his good friend Winston Churchill would be able to protect him.

To avoid the scandal, he went into voluntary exile in the United States, ending up in Bermuda, where he died in November 1940.

The Daily Mail lives on.