If you’ve enjoyed the works of Stephen King, seen the films “Alien” or “Prometheus” or know about the fictional Arkham Asylum in Batman, you can thank H.P. Lovecraft. The horror writer’s work has inspired others for nearly a century.

The mythos that Lovecraft created in stories such as “The Call of Cthulhu,” “The Case of Charles Dexter Ward” and “At the Mountains of Madness” has reached its tentacles deep into popular culture — so much that his creations and the works they influenced might be better known than the writer himself.

Wanting to give the writer his due, fans of Lovecraft are holding this month what they say is the largest celebration ever of his work and influence. It’s billed as the NecronomiCon — named in tribute to a Lovecraft book that gained a reputation for being especially dark and terrible. The convention — this Thursday through Sunday — is being held in Providence, where he lived before dying poor and obscure in 1937; he was just 46.

Howard Phillips Lovecraft was born in 1890. His parents died in an insane asylum — his father when Lovecraft was just 8, said S.T. Joshi, who has written a biography of Lovecraft and edited several collections of his work. He attended three years of high school before leaving because of a nervous breakdown, Joshi said.

Except during a brief and unhappy marriage that took him to New York from 1924 to 1926, Lovecraft lived his life on Providence’s East Side, near Brown University. He wrote his most significant work after returning to Providence, publishing many stories in the magazine Weird Tales. He barely scraped together a living, yet through letters — an estimated 80,000 in his lifetime — he developed a wide network of fellow writers.

Lovecraft said several times that he could not live anywhere but Providence — a sentiment reflected in the gravestone his fans put up decades after his death: “I AM PROVIDENCE,” a line they took from his letters. The grave is visited by fans from around the world, many of whom leave behind trinkets or notes.

Lovecraft was a fan of fellow horror master Edgar Allan Poe, but Lovecraft tackled different themes. He combined horror with science fiction. He also developed what is commonly referred to as cosmicism — the idea that man is inconsequential in the universe, and that there are forces that defy human understanding in the cosmos, represented by gods or beasts who are far more powerful than us, but who are also indifferent to us. To them, we are but ants; get in their way and we will be destroyed.

“A lot of these creatures have baffling physical properties that don’t fit into our perceptions of natural law,” Joshi said. “For him the most terrifying thing that could happen is to defy our understanding of the known laws of physics.”

His most famous creature is Cthulhu. “A pulpy, tentacled head surmounted a grotesque and scaly body with rudimentary wings,” writes Lovecraft, likening it simultaneously to an octopus, dragon and human caricature.

In “The Shadow Over Innsmouth,” he writes of a race of creatures that is a cross among fish, frogs and man. The story inspired a Metallica song, “The Thing That Should Not Be.”

Fans also revel in how detailed and dense Lovecraft’s writing is.

“You’re not going to pick up a Lovecraft novel and just breeze through it,” said Anthony Teth, who is helping to organize the conference.

The author weaves historical and architectural references into his stories, many of which are set in his beloved hometown or other spots he visited in New England.

In Providence, most of the buildings he wrote about are still standing, said Niels Hobbs, 43, a marine biologist when not organizing the conference.

“When you walk the streets of Providence . . . you can see Lovecraft’s Providence. It’s simply everywhere,” he said.

Even so, many Providence residents have no idea of Lovecraft’s connection with the city and his importance in literature. There are no Lovecraft museums or prominent markers in the city.

This week’s conference will include walking tours of Lovecraft’s old haunts, the unveiling of a new Lovecraft bust at one of them, the Providence Athenaeum, and panel discussions on his work, even the negative aspects. He was steeped in the past and suspicious of change; he was also racist and anti-immigrant, themes reflected in his stories including “The Shadow Over Innsmouth.”

In recent years, appreciation for Lovecraft has grown worldwide. There have been film festivals on the West Coast of Lovecraft-themed movies and conferences across the country.

Joshi said the market for horror has always been smaller than for such other genres as science fiction and detective fiction. “I think we’re finally getting to the era where horror fiction can be looked at more than just something to scare you,” he said.