LONDON — Best-selling British horror writer James Herbert, who penned novels such as “The Rats” and “The Fog,” has died suddenly at the age of 69, his publisher said on Wednesday.

Herbert’s editor at publisher Pan Macmillan, Jeremy Trevathan, said the writer died on Wednesday morning in bed at his home in Sussex. No cause of death was given but a spokeswoman for the publisher said he had not been ill.

Herbert wrote 23 novels, was published in 34 languages and sold more than 54 million copies worldwide during a writing career which spanned nearly 40 years.

Four of his novels were made into films: “The Survivor,” “Fluke,” “Haunted” and “The Rats,” whose silver screen title was “Deadly Eyes.”

“Jim Herbert was one of the keystone authors in a genre that had its heyday in the 1970s and 1980s,” Trevathan said in an emailed statement from Pan Macmillan.

“It’s a true testament to his writing and his enduring creativity that his books continued to be huge bestsellers right up until his death.”

Herbert, who was born in London’s East End, worked as an art director at an advertising agency after studying at art college and began writing his first novel when he was 28.

His first novel, “The Rats,” depicting a London overrun by mutant, flesh-eating rodents, was released in 1974 and its first printing of 100,000 copies sold out in three weeks, paving the way for Herbert to become Britain’s leading writer of horror.

Herbert, who designed his own book covers, was awarded the OBE in 2010, the same year he was made the Grand Master of Horror by the World of Horror Convention.

He is survived by his wife Eileen, and their three daughters.