WHEN horror maestro Stephen King describes your novella as “one of the best horror stories ever written,” you know you’re doing something right.

The only trouble is, the guy whom the Pennywise creator was waxing lyrical about had been dead a good couple of decades before King even picked up a pen or bashed out “Carrie” on the typewriter.

Still, posthumous praise is better than no praise at all. And it’s not if Monmouthshire wordsmith Arthur Machen was short of champions during his lifetime.

Oscar Wilde and HP Lovecraft were reportedly big fans of the Gothic horror writer whose works went on to spawn Oscar-winning films.

Although born in Caerleon, Machen was greatly inspired by Abergavenny, its surrounding mountains, and its historic lore.

In his collection of stories set in medieval Monmouthshire, ‘The Chronicles of Clemendy’, one tale deals directly with the people of Abergavenny and an accursed knight.

However, the tale that inspired King to pay such a huge compliment was perhaps Machen’s most famous - The Great God Pan.

Inspired by his childhood visits to the Roman ruins at Caerwent, the novella was heavily denounced upon its release because many critics perceived it as degenerate with overtly sexual connotations.

Oscar Wilde was a fan, though, and called it “un success fou.”

Time and tide soon caught up with Machen and Wilde, and it has since been hailed as a classic and a horror masterpiece.

No stranger to creeping dread and sickening suspense himself, H.P. Lovecraft said of the story, “No one could begin to describe the cumulative suspense and ultimate horror with which every paragraph abounds.”

Stephen King would describe it as perhaps the best horror story written in the English language.

The story is a strange one, and reveals what happens when a doctor performs brain surgery on a girl called Mary in a small Welsh town to “open her mind” to the supernatural and of course, the pagan god Pan.

The experiment ends in disaster, and Mary is rendered a “hopeless idiot.” Yet this is just the beginning of an epic trawl through the darkness that lies at the edge of everything. And to find out more, why not give the book a go?

The likes of the late Mark E Smith did. The frontman of The Fall once said, “I used to be in the Machen society. Been a fan since I was 16. Fanatical and all. He’s one of the best horror writers ever. MR James is good, but Machen’s f****** brilliant. Wrote the first drug story, The Novel of the White Powder. Before Crowley, all of them. Have you read The Great God Pan? Terrifying."

Frankenstein director Guillermo del Toro is also a huge fan and once wrote, "Machen knew that to accept our cosmic insignificance is to achieve a spiritual perspective.”

Fellow Machen fans include Clive Barker, Neil Gaiman, and Alan Moore, who is a prominent member of “The Friends of Arthur Machen” society.

It seems the man from Monmouthshire knew how to cast a long shadow.