Game of Thrones: The cult French novel that inspired George RR Martin

TV series Game of Thrones - about to begin its fourth series - is frequently compared to fantasy creations such as the Lord of the Rings, but it owes an equally large debt to a cult French historical novelist.

Game of Thrones is "fantasy". The TV series, and the books on which it's based, A Song of Ice and Fire by George RR Martin, is set in mythical Westeros.

In the north, a massive wall of ice keeps out barbarian "wildlings" and zombie-like "white walkers". South of the wall, there's a bitter war between rival claimants for the Iron Throne and rule of the seven kingdoms of Westeros. Meanwhile, a princess (Daenerys), exiled to distant lands, is raising three dragons, and has rallied an army of freed slaves.

But Game of Thrones is full of intense political intrigue and gruesome deaths. War and its aftermath are described in brutal detail. Characters have sexual relationships, and sometimes even heroes die unexpectedly. Strip away the supernatural elements, and what is left looks more like a historical saga, chronicling all-too-human conflict.

Maurice Druon (pictured in 2007); The Iron King is the first book of The Accursed Kings

Martin says one of his main inspirations was not fantasy, but a series of novels set in medieval France, little known or read in the English language. Les Rois Maudits (The Accursed Kings) was written by Maurice Druon between the mid-1950s and the 1970s. It's a seven-volume saga chronicling the dynastic fight for the French throne in the early part of the 14th Century, culminating in the Hundred Years War.

"The Accursed Kings has it all," writes Martin, in an introduction to a recently reissued translation. "Believe me, the Starks and the Lannisters have nothing on the Capets and Plantagenets. It is the original game of thrones."

Start reading The Accursed Kings, and the parallels become clear. Westeros has far more in common with Druon's depiction of medieval France, than it does with JRR Tolkien's Middle Earth. Both are feudal worlds, where power is determined by intrigue during peacetime, and bloody retribution during war. In the French court described by Druon, the words of a Martin character ring true: "Only the ladder is real. The climb is all there is."

The Accursed Kings begins in 1314, the last year of Philip IV's reign. The king has crushed the powerful order of the Knights Templar and seized their riches. As the last head of the Templars is burned at the stake - condemned as a heretic on trumped-up charges - he utters an awful curse against the men who have sent him to his fate: "Accursed! Accursed! You shall be accursed to the thirteenth generation of your lines!"

Philip dies soon after, and his family is left to squabble for succession. In A Game of Thrones and The Accursed Kings, there are strikingly similar casts - a feeble but sadistic prince (Louis in the French book, Joffrey in Martin's) a vengeful princess (Isabella, Cersei), and competing Machiavellian schemers (Robert of Artois, Littlefinger). With both writers, the reader navigates the complicated plot through the viewpoints of less powerful figures, caught up in the wake of events.

"They're both epic novels which are character-driven," says Marc Denjean, a French admirer of Druon. "In A Game of Thrones, he [Martin] constructs a big political plot while Druon gets his from history, but in both situations, you're seeing history through the eye of small people."

Margaery Tyrell (Natalie Dormer) and Lady Olenna Redwyne (Diana Rigg)

Putting the two works side by side highlights how Martin's books have become, as some put it, "fantasy books for people who don't usually like fantasy". Martin's technique could be described as historical mash-up - the war between the Starks and the Lannisters resembles the War of the Roses, the Dothraki tribe - into which Daenerys is married at the beginning of the sequence - is akin to Genghis Khan's Mongol hordes, while the Ironborn warriors have much in common with the Vikings. And the Wall of Westeros brings to mind either Hadrian's Wall or the Antonine Wall in northern Britain.

It's like history - but with the added suspense of not knowing who will win or lose. This element of Martin's work has gained him the admiration of some historians. "Different events - and different periods - elide to consistently potent and surprising effect. In Game of Thrones, episodes from the history of our own world lie in wait for the characters like booby traps," writes Tom Holland, author of Rubicon and Persian Fire, about the series.

For others, Game of Thrones has itself been a gateway into historical study. US writer Jamie Adair was inspired to begin the History Behind Game of Thrones blog. "To be honest I only expected to get a couple of blog posts out of it," he says (it's now about 180 pages long). "I didn't think the novels had that many historical parallels besides a few obvious ones with the War of the Roses.

"I keep writing the blog because it challenges me to explore new areas of history and look at it in different ways. For example, before the blog, I never would have chosen to read about siege warfare in the ancient world… but I end up seeing different patterns in history as a result."

Maurice Druon, who died in 2009, is barely known in the English-speaking world, but he enjoyed a considerable reputation as a man of letters in his home country. During World War Two he served under Charles de Gaulle and penned the patriotic anthem Chant Des Partisans. Later in life, he became head of the Academie Francaise, the august body which decides what is and what isn't allowed in the French language. Druon was staunchly against the creeping Anglicisation of French, although he apparently approved the words "tweed" and "birdie" into French dictionaries.

Arya Stark (Maisie Williams) and Sandor Clegane (Rory McCann)

When Druon died in 2009, it was these achievements on which obituarists focused, not his historical saga - which seems to have been as Druon wished. "Les Rois Maudits was written to make money very quickly," says the Independent's French correspondent John Lichfield. "He himself was not very proud of it." Lichfield knew Druon, who he describes as "a sweet, generous, humorous man" who was also an ardent Anglophile. "He was someone who you came across a lot in English receptions at the embassy."

Denjean says that Les Rois Maudits passed from cult to mainstream success with a screen adaptation in the early 70s - a sort of French equivalent to I, Claudius. "It was a primetime TV show - these were the days when you had one or two channels and everyone would watch together." Druon was also among the approved list of French novelists approved in the USSR at that time. Later, Vladimir Putin was an admirer of Druon, meeting him several times.

Druon's books have waned in popularity even in France in recent years, according to Lichfield. "I wonder how many French Game of Thrones fans have even heard of him," he says. But history may be coming full circle. The Accursed Kings sequence is being reissued in English translation, complete with Martin's introduction. It may be that Druon will find a whole new audience on the recommendation of the writer his books influenced.

Follow @BBCNewsMagazine on Twitter and on Facebook