The Challengers of the Unknown is a group of fictional characters first drawn by Jack Kirby for DC Comics. This quartet of adventurers explored science fictional and apparent paranormal occurrences and faced fantastic menaces. The scripts for the first stories are often credited to Dick and Dave Wood, two brothers who also wrote other Kirby-illustrated material, such as the "Sky Masters of the Space Force" comic strip; but others have claimed that Kirby created the Challengers himself or together with former partner Joe Simon.

The group debuted in Showcase #6 (February 1957) as acquaintances who miraculously survived a plane crash unscathed. They concluded that since they were "living on borrowed time", they should band together for hazardous adventures. The four — Kyle "Ace" Morgan, Matthew "Red" Ryan, Leslie "Rocky" Davis, and Walter Mark "Prof" Haley — became the Challengers of the Unknown.

The inspiration for the Challengers' adventures were old serials, war movies, and drive-in science fiction. Superhero comics had mostly vanished by the mid-1950s; the revival of the Flash, often seen as marking the return of the super-heroes to popularity, had occurred only a few months earlier, in Showcase #4. As larger-than-life heroes without super-powers but having super-adventures, the Challengers helped pave the way for the 1960's superheroes. Like war movies, their "squad" had the standard archetypes: Ace, the hotshot pilot and leader; Rocky, strong and dumb; Prof, the skinny brain; and Red, the hothead daredevil. The stories had weird menaces, fistfights, wild vehicles and gadgets, spectacular terrain, daring escapes, and a sense of humor.

The most noted influence of this creation was Kirby's next major continuing series, The Fantastic Four, which was essentially the Challengers as a superhero family, complete with a similar origin. Both groups were quartets who resolved to band together after a crash landing; but the Challengers lacked the strong characterizations and much of the humor that distinguished the Fantastic Four. In "Challengers of the Unknown" #3, Rocky was shot into space and returned with multiple superpowers including invisibility, flame throwing, freeze-ray throwing, giant-growth, super-speed and super-strength.

The series continued in Showcase for three more appearances (#7, 11, 12) then moved to its own title, considered among Kirby's most notable in that period. After 12 issues total, Kirby moved on, and while the title continued through issue #75 (Aug.-Sept. 1970, followed by intermittent reprint and revival issues from 1973-78), the series never achieved the same level of acclaim. It was a typical DC B-List comic, a steady seller like the Doom Patrol and Sea Devils.

Soon famous, the Challengers accepted many "unknown challenges" from the Pentagon, mad scientists, and people with a problem. Over time the "Challs" established the hollowed-out Challengers Mountain as headquarters. Later they adopted an hourglass logo to symbolize time running out. They encountered genies, common and sophisticated thieves, rocs, aliens and robots good and bad, mad scientists, and super villains. Their adventures followed the flow of other DC comics starting with "Strange Adventures", veering toward superheroics (during the Bat Craze), to occult menaces, through Bermuda Triangle weirdness, and finally to cancellation (1979). The Challengers traveled through space, time, and other dimensions. Guest stars included the Doom Patrol, Deadman, Swamp Thing, Jonny Double, and Sea Devils.

During a one issue crossover story with the Sea Devils in Challengers of the Unknown issue #47 they fought the criminal group known as Scorpio. June Robbins, a computer genius and archaeologist, joined the Challengers for many adventures as an "honorary" or "girl" Challenger, starting in their appearances in Showcase.

In a short-lived 1977 revival, the Challengers were a four-man, one-woman team again. The first came back in Super-Team Family #8-10, before getting their own title back with #81. They were joined by Deadman and Swamp Thing. June Robbins got a uniform and official status. No explanation for June's joining was given.

Their title was canceled with #87 in 1978, but they continued their storyline in Adventure #493-497. They also appeared in issues of Super-Team Family.

Volume 2

The Challengers were revamped with a "Dark Knight" cast in Volume 2 (1991) by Jeph Loeb and Tim Sale. The Challs were semi-retired, their mountain a theme park, and their adventures disregarded as cooked-up articles in "The Tattletale". Other-dimensional experiments and a bomb blew up the mountain and nearby town. Prof and June were presumed killed. Red, Rocky, and Ace were tried and ordered to disband. The three drifted apart, dogged by a ghostly Prof and June, then reunited to defeat a space-demon causing worldwide suicides and madness. "The New Challengers of the Unknown", including ghostly Prof and June, were poised to take on menaces in the dark corners of the DCU. Loeb planned a second miniseries to reset the Challs to youth and heroism, but it never materialized.

The mini series was 8 issues. It was reprinted in trade paperback as Challengers of the Unknown Must Die! in 2004.

Volume 3

The Challengers were revamped again by Steven Grant in Volume 3 (1997). Four new Challengers pursued X-Files-like horrors. They were Clay Brody, NASCAR driver; Brenda Ruskin, physicist; Kenn Kawa, radical games designer; and Marlon Corbet, commercial pilot, who also miraculously survived a plane crash. They stopped sacrificial wackos, drug-juiced zombies, vengeful ghosts, Amazon cults, Lovecraftian monsters, mass suicides, humming buildings, and other oddities. They were advised by Rocky Davis, older and grayer and alone. It was eventually revealed the original Challengers were dematerialized by a mad scientist's ray-weapon. The same ray caused both plane crashes, as well as others. Soon the original Challs reappeared, helped the young Challs defeat the madman, then walked back into oblivion (minus a wounded Rocky) to shut down a runaway Tesla field. The young Challengers vowed to fight on - until cancellation in 1998 with issue #18.

The missing Challengers - Ace, Red, Prof, and June - were discovered by Superboy in Hypertime. The team was waging guerrilla war against Black Zero (a Superboy variant). With Black Zero defeated, the team returned to Earth, but lost Red Ryan along the way. Reunited with Rocky in Metropolis, hosted by Rip Hunter, the original Challengers vowed to explore Hypertime, "the greatest unknown," to find Red.

Two Challengers partook in Infinite Crisis. Rocky Davis and Prof Haley helped stem the escape of prisoners from Blackgate Prison (Villains United: Infinite Crisis Special 1) and Rocky fought in the Battle for Metropolis (Infinite Crisis 7).

Other Info

In Amalgam Comics, the Challengers were amalgamated with their super-powered counterparts, the Fantastic Four, to form the Challengers of the Fantastic.