“Imperius Rex!” is the war cry of the Sub-Mariner (known as Namor to his friends), who greeted comic book fans Aug. 31, 1939, in “Marvel Comics” No. 1. The Sub-Mariner was one of a parade of characters who followed in the wake of the 1938 arrival of Superman. Other characters premiered in that issue, but Namor, whose mother is from the sunken city of Atlantis and whose father is human, arguably has the richest history.

“He was comics’ first antihero,” Mark Waid, a veteran comic book writer and editor, wrote in an e-mail interview. “Namor’s goal wasn’t to rescue kittens or punch criminals — it was to lead an Atlantean army against the air-breathers of America.”

Here are some big issues in the swim-up to his 80th.

May 1940: Marvel Mystery Comics No. 9

Both the android hero known as the Human Torch and Namor were in Marvel No. 1, but they did not meet until a story in Marvel Mystery Comics Nos. 8-10 found them at odds. The Torch is out to stop Namor from wrecking New York City. The clash ends in a stalemate: Namor agrees to leave, and the Torch drops his pursuit.

Feb. 1962: Fantastic Four No. 4

Namor makes a permanent return to comics in this 1962 issue by Stan Lee and Jack Kirby. Here the new Human Torch finds Namor — who has amnesia — in a men’s hotel in New York City. Namor regains his memory and rage. The Fantastic Four repel him, but he turns up again in No. 9. Enter Namor, movie mogul. He uses sunken treasures to finance a film starring his four favorite enemies, who sign on despite having no script because of financial troubles. Namor’s true goal: to make Invisible Girl his bride. He fails, but profits from the film restore the wealth of the Fantastic Four.

August 1973: Sub-Mariner No. 67

Namor gets a new costume, but the reason is medical, not sartorial. A nerve gas explosion leaves him unable to retain moisture while on land. This could free the world from his tyranny, but Reed Richards of the FF designs this suit, which recycles the moisture in Namor’s pores, to help him survive. Richards: “He’s a ruler of a nation — concerned for his people. And he’s a human being — almost — with a right to live.”

Nov. 1989: Marvel Age No. 84

The Marvel magazine previewed the 1990 Namor series by interviewing its writer/artist John Byrne. The cover was a harbinger of Sub-Mariner’s next evolution: a tycoon running Oracle, a company specializing in ecological issues. “Namor’s concern is that the surface world is rather sloppy in taking care of the planet we all share,” Byrne said.

Jan. 2019: Invaders No. 1

Namor is back in a conquering mood. In this, he is pitted against some of his former allies from World War II — including Captain America. Later, he transforms some humans into Atlanteans against their will, and learns that Charles Xavier inadvertently allowed an evil presence to enter Namor’s mind, suggesting that he may not have always been responsible for his evil deeds. Namor takes the news hard but continues forward on his destructive path.