Jack Katz, a comic-book artist and writer whose 768-page magnum opus, “The First Kingdom,” published in installments over a dozen years starting in 1974, was widely credited with helping give birth to the long-form graphic novel, died on April 24 in Walnut Creek, Calif., east of San Francisco. He was 97.

His death, in a hospital, was confirmed by a friend, Brian Miller.

Mr. Katz published “The First Kingdom,” a sprawling blend of fantasy and science fiction with philosophical underpinnings, in two books every year until he reached Issue No. 24 — a number he arrived at intentionally, as that was the number of books in Homer’s epics, the “Iliad” and the “Odyssey.”

Mr. Katz’s own epic begins after a nuclear apocalypse, as small bands of humans try to survive among dinosaurlike mutants, monsters, gods and other fantastical beings. It becomes “a complex science fiction epic that tells of man’s migration into space, the ensuing galactic battles, and the great mystery of mankind’s origin before the fall of civilization,” as the reference site Lambiek Comiclopedia describes it.

Published in installments over a dozen years starting in 1974, “The First Kingdom” is widely credited with helping give birth to the long-form graphic novel.Credit…Jack Katz/Titan Comics

Channeling the anything-goes spirit of the underground comics scene of the 1960s and ’70s, Mr. Katz brought this sweeping tale to life with lavish, multilayered illustrations, obsessing over the tiniest details. In keeping with the counterculture ethos, there was plenty of nudity, too.

His enormous ambition paid off. The revered comics pioneer Will Eisner once called “The First Kingdom” “one of the most awesome undertakings in modern comic book history.” Jerry Siegel, who created Superman with Joe Shuster, wrote that “reading ‘The First Kingdom’ is like seeing captured on paper glimpses of a dream world depicted by an artist with remarkable creative vision.”