NEW YORK, NY.- Nelson DeMille, a beloved and prolific author whose propulsive thrillers featuring terrorist hijackings, Russian spy schools, gruesome murders, Mafia kingpins, wartime crimes and military malfeasance made him a publishing juggernaut, died Tuesday in Mineola, New York. He was 81.

His death, at a Long Island hospital near his home in Garden City, was from complications of esophageal cancer, his son, Alex said.

DeMille’s writing “brought you into wonderful worlds,” said Sally Richardson, publisher at large for Macmillan, who knew him for decades.

“His books were fun and literate,” she added, in an interview. “He had a grasp of human nature and a sense of humor, and he got all kinds of people — the down-and-outs and the sophisticates. He defied category. Everyone wanted to publish Nelson.”

DeMille was the author of 23 books, 17 of which were bestsellers and all of which remain in print. At his death, a total of 58 million “DeMilles” had been sold.

The burly and genial DeMille hadn’t planned on a full-time writing career.

As a young man, he served as an Army platoon leader in Vietnam during the Tet offensive in 1968. Afterward he earned a degree in history and political science from Hofstra University, thinking he might be an architect or a lawyer. Instead, he went to work as an insurance fraud investigator and wrote pulpy police procedurals on the side, earning $1,500 a manuscript.

“It was more of a kitchen table hobby,” he said.

Then his publisher asked him to write a biography of Barbara Walters, “The Five-Million-Dollar Woman” (1976). It came out under a pseudonym, Ellen Kay, the first two names of his wife at the time.

“The book did OK,” DeMille wrote later, “but I was clearly going nowhere as a writer, no matter what name I used on the cover.”

The turnabout in his fortunes came two years later, with his breakout novel, “By the Rivers of Babylon,” about a Middle East peace mission that goes horribly wrong. It sold for $425,000 (more than $2 million in today’s money), an enormous sum for an unknown author. Sales were brisk, but with The New York Times on strike that summer, it didn’t make its bestseller list.

DeMille’s narrators were of a type: world-weary and wisecracking veterans and police officers. His most well-known character was John Corey, a former New York City cop working on contract as an agent for a federal anti-terrorist task force. Corey is fond of cold beer, crude one-liners and meaty, complicated cases. He dislikes yuppies, poseurs and “schmucks from the Feds.”

“You can hear Nelson’s humor in Corey’s voice,” said Susan Lucci, the soap opera star and an old friend of DeMille’s (his uncle built her childhood home in Garden City). “His very well-lived voice.”

Early on, DeMille had hoped one day to turn his combat experience into “the great American war novel.” But that effort would not appear until 1985, with “Word of Honor,” which imagined a My Lai-like atrocity and an investigation into its horrors years after the fact.

Time magazine praised the novel for its “gunmetal ring of authenticity,” describing it as “‘The Caine Mutiny’ of the ’80s, a long, over-the-shoulder look at a time that grows larger as it recedes from sight.”

DeMille, who favored blue blazers and wore a trim beard, delivered a book every two years, writing in longhand on legal pads with a No. 1 pencil. “Writing was never meant to be a two-handed enterprise,” he told the Times in 2009, “and, besides, this frees up my left arm to hold a cup of coffee or flip through a research book.”

His book-lined office, which he called Area 51, was filled with the scent of Marlboro cigarettes, black coffee and pencil shavings and overseen by a bust of Julius Caesar — DeMille was a Roman history buff — variously wearing an assortment of accouterments. (It recently wore a T-shirt emblazoned with the cover of “The Cuban Affair,” his 2017 caper about a down-on-his-luck charter boat captain and combat veteran in Key West, Florida, who’s been hired to find a stash of cash hidden in Cuba.)

DeMille’s handwriting, a furious scrawl, “was atrocious,” said Patricia Chichester, his longtime assistant, who gamely typed his manuscripts into a computer. She said it took her five years to fully decipher his penmanship.

DeMille received thousands of fan letters each year, she added, and answered every one. DeMille devotees sent portraits they’d made of him and pictures of themselves reading his books in faraway places. They sent bottles of wine and Dewar’s White Label (his favorite scotch), cookies iced with renditions of his book covers and, once, an Adirondack chair painted to mimic the cover of “The Gatehouse,” his 2008 sequel to “The Gold Coast” (1990), about a high-WASP family’s clash with the Mafia kingpin who moves in next door.

“What makes ‘The Gold Coast’ glitter is Nelson DeMille’s sharp evocation of the vulpine Bellarosa,” Joanne Kaufman wrote in the Times, referring to the character of the Mafia don, “and of Sutter” — the protagonist, who is married to a rather gothic old-money scion — “a wonderfully sardonic, self-mocking man betrayed by a midlife crisis.”

Nelson Richard DeMille was born Aug. 23, 1943, in Jamaica, Queens, and grew up in nearby Nassau County, one of four brothers. His mother, Antonia (Panzera) DeMille was a homemaker; his father, Huron DeMille, was a builder.

Nelson graduated from Elmont Memorial High School and attended Hofstra for three years before joining the Army and rising to lieutenant. He earned a Bronze Star, among other commendations, for his service in Vietnam, where a third of his platoon was killed or wounded. He returned to Hofstra in 1969 and graduated the next year.

In addition to his son, Alex, with whom he collaborated on two novels — their third, “The Tin Men,” will be published next year — DeMille is survived by a daughter, Lauren, and another son, James. His marriages to Ellen Wasserman and Virginia Witte ended in divorce. His third wife, Sandra Dillingham, died in 2018.

Many of DeMille’s novels were optioned for film rights, but only one, “The General’s Daughter” (1992), a military mystery about a rape and murder, was adapted into a major motion picture.

The movie, in which DeMille had a writing credit, was released in 1999 starring John Travolta as the investigator of the case, Madeleine Stowe as the rape expert who teams up with him, and James Woods as a high-ranking officer who is a suspect. In her review for the Times, Janet Maslin found the film underwhelming.

Impishly, DeMille took a dig at Maslin in a later book, “The Lion’s Game” (2000), about a vengeful Libyan terrorist and a horrific plane crash. As the book concludes, John Corey riffs in an aside about the Times and its movie critic.

“Maslin was reviewing a box office smash,” Corey declares, “an action-adventure Mideast terrorist flick of all things, which I think she didn’t like, but as I say it’s hard to follow her prose or her reasoning.” Corey adds, “I made a mental note to see the movie.”

DeMille often tucked Easter eggs into his work, such as a character reading a book by Stephen King, whom he admired. He participated in charity auctions in which bidders could vie to have characters in future books named after them.

And at the conclusion of “Wild Fire” (2006), a John Corey vehicle that imagines a nightmarish response to the 9/11 attacks, DeMille had a bit of fun with his acknowledgments.

Among the many boldface names he thanked, using boldface type to do so, were the emperor of Japan and the queen of England, “for promoting literacy”; William S. Cohen, the former secretary of defense, “for dropping me a note saying he liked my books”; Don DeLillo and Joan Didion, “whose books are always before and after mine on bookshelves, and whose names always appear before and after mine in almanacs and many lists of American writers — thanks for being there, guys.”

And he thanked Paris Hilton, “whose family hotel chain carries my books in their gift shops.”

This article originally appeared in The New York Times.