Les Daniels, one of the earliest historians of comic books — from the launching (off the doomed planet Krypton) of Superman in 1938 through the countercultural comix movement of the ’60s — and an author of horror novels, died on Nov. 5 at his home in Providence, R.I. He was 68.

The cause was a heart attack, said Diane Manning, his sister and only immediate survivor.

Mr. Daniels wrote 10 nonfiction books — among them histories of superheroes and of major publishers like DC and Marvel — and five works of fiction, all revolving around a globetrotting, time-traveling vampire, Don Sebastian de Villanueva.

But he is perhaps best known, particularly among aficionados, for his 1971 book, “Comix: A History of Comic Books in America.” Starting with the days when pulp fiction fused with newspaper cartoons, Mr. Daniels documented how the golden age of comic books — pretty much starting with an infant placed on a rocket ship from Krypton to become Superman on Earth — evolved into a period of turmoil in the industry after a noted psychiatrist, Fredric Wertham, published “Seduction of the Innocent” in 1954. Focusing on the darker elements of the genre, horror and crime, Dr. Wertham saw comics as a cause of juvenile delinquency. His assertions were the subject of Senate hearings and prompted the industry to adopt a code of self-censorship.