'You couldn't make it up': How 'The King's Man' became a 'crazy' World War I history lesson

From related rulers to some seriously oddball villains, director Matthew Vaughn found a lot of World War I history to be stranger than fiction, enough to be a perfect background for the earliest days of his over-the-top British secret agent world.

The “Kingsman” movie franchise gets the prequel treatment with “The King’s Man” (in theaters Wednesday), a period action film where the Duke of Oxford (Ralph Fiennes) creates a covert spy organization – one that includes his soldier son Conrad (Harris Dickinson) – and takes on a cabal of notorious tyrants and masterminds bent on destroying England.

In 2014’s “Kingsman: The Secret Service,” Harry Hart (Colin Firth) explains to young hero Eggsy (Taron Egerton) that Kingsman was founded in 1919, and Vaughn fills in the blanks leading up to its birth with “King’s Man.” In doing his research, the filmmaker found aspects of history repeating itself.

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“A lot of what happens in this movie is as relevant now as it was a hundred years ago: being wary of your leaders, war breaking out for all the wrong reasons, Spanish flu and COVID, all of these similarities back then to what we're going through,” the filmmaker says.

With future period prequels in mind, “I’d love to go through each decade of history, but more importantly, the history of espionage and who the enemies were and which allies were formed and broken," he says. "And let kids see what history's about in a way that doesn't bore them to death but they might learn from it.”

Vaughn explains some of the major World War I moments and real historical figures he weaves into “The King’s Man”:

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Franz Ferdinand takes a wrong turn into infamy

The 1914 assassination of Archduke Ferdinand of Austria is regarded as the spark that ignited the war and that incident gets seen through the “Kingsman” lens: Working for the mysterious puppet master known as The Shepherd, Bosnian Serb nationalist Gavrilo Princip (Joel Basman) throws a bomb at Ferdinand’s motorcade in Sarajevo, which is batted away by Fiennes' umbrella-wielding duke. But later that day, the royal vehicle ends up down a side street, mere feet from the cafe where Princip went after the first attempt, and Princip shoots the king and his wife. “That happened,” Vaughn says. “I was like, ‘I can't believe this.' "

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A family rivalry goes global with three kings

Believe it or not, the trio of rulers at the heart of the conflict – England’s King George V, Russia’s Tsar Nicholas II and Germany’s Kaiser Wilhelm II – were all cousins, and because they looked alike, Tom Hollander plays all three roles in “King’s Man.” “Google King George and Tsar Nicholas. You cannot tell the difference between the two guys,” Vaughn says. “They changed their uniforms at state banquets for the fun of it: One would pretend to be the tsar and the other the king and no one would notice.” However, the origins of this “family squabble” dated to George and Nicholas bullying the Kaiser about his undersized left arm. “He was so angry, he goes, ‘Well, I’m going to have a big navy and show my cousins who's the boss,' " Vaughn says.

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Rasputin is the weirdest dude of them all

Known as Russia’s “Mad Monk,” Grigori Rasputin (Rhys Ifans) is one of the most infamous personalities appearing in “The King’s Man” and also key to The Shepherd’s plan to get Russia out of the war, thus letting Germany focus all its energies on battling England. “This guy was so larger than life,” says Vaughn, who worked real-life legends of his sexual obsessions and sweet tooth into an undercover operation involving our heroes. Rasputin also fights the heroes with Cossack dance moves set to the “1812 Overture”: “All the dancing basically was Russian kung fu,” Vaughn says.

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‘The King’s Man’ brings together a president and a sexy spy

Vaughn found it “very odd” that America waited till 1917 to dive into World War I: President Woodrow Wilson vowed not to go to war, but the Zimmermann Telegram, a secret message proposing an alliance between Germany and Mexico, certainly gave him reason to get involved. Vaughn added a little more cinematic intrigue – and the 1910s equivalent of a sex tape – to that subplot by having Mata Hari (Valerie Pachner), one of The Shepherd’s crew and a real-life femme-fatale spy, blackmail Wilson, who Vaughn says actually kept “naughty letters” from a secret relationship. The craziest historical bit for the director, though, was the actual telegram that went public: “You couldn't make it up.”

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The movie has big plans for an obscure baddie

The Shepherd’s right-hand man is Erik Jan Hanussen (Daniel Brühl), and for those who’ve never heard of him, he’s an Austrian guy worth a web search. “He becomes very important in history, sadly for all the wrong reasons,” Vaughn says about the astrologer who was, "in a weird way,” Hitler’s Rasputin. “When I was reading about him, I was just like, ‘My God, there's someone as crazy as Hitler out there.’ I just felt there was something about that character for later on. If we get to make another movie, he becomes the new horrible villain behind the villains that we already know.”

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This article originally appeared on USA TODAY: 'The King's Man' fact check: What's true, fake in WWI spy prequel