Two of the upcoming comic-inspired movies I'm most looking forward to are Captain Marvel from Disney/Marvel, and Shazam from WB/DC. Both star a superpowered character who goes by the name Captain Marvel, although the hero of Shazam might end up being called Shazam. Understandably, there's a little confusion regarding the name "Captain Marvel" and how it relates to various characters. Not only have there been various characters in both the DC and Marvel universes named Captain Marvel, they have generally also gone by various other names. There are also various Marvelmen, Marvel Boys, Marvel Girls and Ms. Marvels, not all of which are related to the Marvel comic publishers. How to make sense of all this? Well, here goes:
Fawcett, National and DC
The original Captain Marvel was the star of a strip published by Fawcett Comics, his initial apperance being in issue two of Whiz Comics in 1940. At first glance, Captain Marvel was a Superman rip-off, and it was certainly the success of National Comics' Batman and Superman comics that led to the creation of Whiz Comics and its characters. The origin of Captain Marvel was entirely different, however. He was teenager Billy Batson, who encountered the wizard Shazam, who granted him the power to transform into Captain Marvel by uttering the word "shazam!". The magical incantation granted Billy the wisdom of Solomon, the strength of Hercules, the stamina of Atlas, the the power of Zeus, the courage of Achilles and the speed of Mercury. He had very Superman-like powers and appearance, and yes, this did eventually get Fawcett comics into trouble. However, during the 1940s Captain Marvel's adventures were the best-selling American superhero comics of all, outselling his inspiration. During that golden era, a whole Marvel Family was created, including Captain Marvel Jr (really the young boy Freddy Freeman) and Mary Marvel (Billy's twin sister Mary). While Mary got her powers from saying "Shazam!" like her brother, Freddy had to say "Captain Marvel," so was always a second-tier sidekick to the true Captain Marvel. There was also a short-lived spin-off title called The Marvel Family, which featured other, non-powered members of the Marvel family, plus Marvel Lieutenants and even a Marvel Bunny.
By 1953, however, the tide was turning. National Comics was now Detective Comics Publishing (later DC Comics), and a lawsuit between DC and Fawcett over Captain Marvel's similarities to Superman resulted in the cancellation of the line. DC eventually required the rights and finally complete ownership of Fawcett's stable of characters, and made plans to bring back Captain Marvel as one of their own heroes - one of the few who could go toe-to-toe with Superman. Various attempts to revive the character in the 70s and 80s, including an alternative version named Captain Thunder, had not been very successful, but in 1991 the graphic novel The Power of Shazam! reintroduced the character for good. Captain Marvel has survived the many reboots of the DC line, and still exists, with a revamped backstory, in the New 52.
The problem, of course, is that during Billy Batson's period off the stands, Timely Comics, publishers of such characters as Captain America and the Human Torch, has changed their name to Marvel. To protect their copyright, Marvel created their own superhero named Captain Marvel, who premiered in Marvel Superheroes in 1967. After this, all the new DC Captain Marvel products were sold under the name Shazam! By 2011, the character had stopped being referred to as Captain Marvel even within the comics' story material, and was now known as Shazam (formerly the name of the wizard). While many fans still refer to him as Captain Marvel, this does fit with a proposed future mythology for the character, in which he will one day become the new wizard Shazam and choose a new Captain Marvel. Captain Marvel Jr, for his part, split from the Marvel family for a time and changed his name to CM3, while the New 52 version wishes to be known as King Shazam. There are other Captains Marvel in the DC multiverse, as well. One of Batson's most nefarious enemies is Black Adam, an evildoer who also wields the power of Shazam (and who will be played by Duane Johnson in the upcoming movie). There's also a version of the character on the parallel Earth-3, only in this version of events, it is Lex Luthor who is granted the power, whenever he says "Mazahs!" Really.
When Marvel pinched the rights to the character name, they began a series of characters called Captain Marvel, a legacy title that has been handed down and that, unlike Captain America, say, has no one character who dominates its history. The first Captain Marvel is actually called Marr-Vell, and is a member of the alien race the Kree, sent to Earth to monitor them only to eventually break away and ally with the human race. In a grim turn of events, Marr-Vell died of cancer in the graphic novel The Death of Captain Marvel. The second Captain Marvel was Monica Rambeau, a character created in 1982 and, unusually, a black female superhero. Rambeau was bombarded by cosmic energies, granting her the ability to convert to electromagnetic energy, and allowing her extreme speed, intangibility, energy blasts and so on. As Captain Marvel, she led the Avengers for some time.
Marr-Vell's son, Genis-Vell, became the third Captain Marvel, and after some initial friction, Rambeau conceded the name. She has since been known as Pulsar and Photon (neither of which is a name unique to her, because that would be too simple) but now goes by the name of Spectrum, and is part of the Mighty Avengers team, acting as their field commander. For some, Rambeau is the definitive Captain Marvel, and while she is both a major female member of the Avengers and a real heavy hitter, she is not the Captain Marvel who will be headlining her own Marvel movie.
Now, Genis-Vell, Marr-Vell's genetically engineered son, had a hard time as the Captain, going mad and destroying the universe (he did fix it up again though). Genis took the name Photon (requiring Rambeau to change her name again, and yes, this is confusing) leaving the captaincy open. It was taken next by his sister, Phyla-Vell, who came to exist as part of the strange effects of Genis's recreation of the universe. Phyla's name is a terrible pun of the part of writer Peter David. She has since become known as Quasar and then Martyr, became one of the Guardians of the Galaxy, and died in battle. The fifth Captain Marvel was a Skrull sleeper agent known as Khn'nr, a shape-shfiting alien who took on the identity of Marr-Vell. The Marr-Vell identity became dominant, so for a short time it was as if the original Captain Marvel was back. He died too.
Marvel Boys and Marvel Girls
While Captain Marvel didn't come to Marvel until relatively late on, Marvel-monikered heroes graced its pages even before it was called Marvel Comics, back when it was called Timely Comics, and then Atlas Comics. The first such character was Marvel Boy, aka Martin Burns, a young man who wielded the power of Hercules in the Forties. In fact, there were two Martin Burnses, according to the official Marvel history, an attempt to make sense of two wildly contradictory origin stories. Supposedly they were both active under the name Marvel Boy at the same time, because this isn't confusing enough. In the 50s, Robert Grayson received cosmic bracelets from the Eternals to become Marvel Boy in his own title from Atlas Comics. And he grew up on Uranus. This Marvel Boy was revived in the 70s and revamped as the Crusader, and become part of the superhero team the Agents of Atlas in 2001. His bracelets were later donned by Wendell Vaughn, who became the next Marvel Boy, later Marvel Man, and finally Quasar. Yes, this is also the name later taken by fourth Captain Marvel, Phyla-Vell, after she acquired the cosmic armbands.
The fifth Marvel Boy was Vance Astrovik, a mutant who later took on the hero name Justice. To be extra confusing, another version of Vance Astrovik better known as Vance Astro became a member of the original Guardians of the Galaxy in an alternative timeline in the 31st century. The two Vances have even met up and worked together. The original Vance was followed by another mutant, the even more powerful David Bank. The best known Marvel Boy, however, was Noh-Varr, another member of the Kree race. He sided with the Earth during the Skrull invasion and took on Norman "Green Goblin" Osborn's offer of joining his "Dark Avengers," becoming the sixth carrier of the title of Captain Marvel.
There have been four Marvel Girls. The first was the mutant girl Jean Grey, founding member of the X-Men and also known by the name Phoenix, although generally referred to, unusually, by her given name in most things these days (particularly on TV and film). She was, of course, played by Famke Jansen in the Fox X-Men movies although will presumably be recast for X-Men Apocalypse. Jean Grey has died numerous times, and it never sticks. She and her husband, Scott Summers aka Cyclops, share some of the most convoluted storylines and family tree in the Marvel universe, covering multiple alternative timelines and potential futures. Their daughter Rachel, from one such future, is the third Marvel Girl. The second was Valeria Richards, the daughter of Reed Richards (Mr Fantastic) and Sue Storm (Invisible Girl/Woman) in yet another alternative timeline. There was also a fourth Marvel Girl in yet another alternative future, Dream Richards, the daughter of Rachel Grey and Franklin Richards, Valeria's brother. A proper Marvel family.
Carol Danvers, a USAF officer, debuted in the 60s in Marvel Super Heroes, where she was caught in an explosion alongside Marr-Vell. Although injured, she absorbed some of his Kree DNA, since this is what happens in explosions in comics. Now equipped with flight, super strength and other abilities, she took on the name Ms. Marvel, and received her own title. Danvers has gone through some pretty horrendous stuff in her long comics career, including an ill-judged rape storyline and a twisted encounter with the X-Man Rogue, which ended up granting Rogue enhanced powers but also carrying round a copy of Danvers in her head. Danvers later received enhanced powers at the hands of another alien species, and took on the name Binary. She's also been known as Warbird, but eventually settled back into being Ms. Marvel. Danvers first got the title of Captain Marvel in another alternative reality, in the House of M event, before finally taking on the position in the mainstream comics run in 2012. Since then, the Danvers-headed run of Captain Marvel has become enormously popular. As well as being a member of both SHIELD and the Guardians of the Galaxy, Danvers has been the subject of continual fan requests for the cinematic treatment. And so it is this Captain Marvel who will be getting her own major movie release in 2018, as part of the third phase of the Marvel Cinematic Universe.
This has of course left a vacancy for the position of Ms. Marvel. Although there have been two other shortlived Ms. Marvel's in the past - Sharon Ventura, who later mutated into the She-Thing, and Karla Sofen, better known as Moonstone, who became the evil Ms. Marvel as part of the Dark Avengers. The current Ms. Marvel is Kamala Khan, a young Pakistani American girl who sees Danvers as her idol, and takes on the name after her Inhuman powers are triggered. Given that both Captain Marvel and the Inhumans have movies coming up (and the Inhumans are also involved in Marvel's Agents of SHIELD on the TV), it's not impossible that we'll see Kamala on screen sometime.
It's also worth briefly mentioning that Danvers appears in other Marvel lines, set in yet more alternative timelines. The Ultimates line features a non-superpowered Captain Danvers who is at one time involved with Mahr-Vehl, the Captain Marvel of that reality. She also features prominently in the Marvel Mangaverse, in which she actually becomes Captain America. As Captain Marvel, though, Danvers is probably the premier female superhero of the mainstream Marvel line. I mean, she represents the Earth to the universe at large, that's pretty impressive.
The Marvelman Debacle
Although most committed comics fans get their comics from specialist shops that import them from the States, there's a tradition of British publishers selling reprinted American comics in newsagents on the high street. Fawcett's Captain Marvel and its spin-offs were published here by L. Miller and Sons. Ltd, who found themselves in a pickle when Fawcett cancelled their entire line following the dispute with DC. So Miller's simply produced their own knock-off version of the good Captain, under the name Marvelman. This was young Mickey Moran, who received his powers from an interstellar wizard-scientist and became Marvelman when he uttered the word "Kimota!" (atomic backwards, sort of). He got his own version of the Marvel family, with Dicky Dauntless as Young Marvelman and Johnny Bates as Kid Marvelman, each swapping their child bodies with superpowered adult forms when they exclaimed "Marvelman!"
The original Marvelman run carried on till 1963, when it was canned. It was revived in 1982 by Dez Skinn and Alan Moore for the first issue of Warrior, an anthology comic in the vein of 2000 AD. Having already revamped the poorly conceived Marvel character Captain Britain (which included another version of the Marvelman character, briefly glimpsed as Miracleman in another timeline), Moore began his career defining deconstruction of the superhero genre by crashing wholesome hero Marvelman into the real world. The adult Mike Moran, plagued by nightmares from his forgotten time as Marvelman, rediscovers his powers. His journey of discovery leads him to Johnny Bates, who has remained in his Kid Marvelman guise through the years and matured to become supremely powerful. Forced back to be thirteen-year-old Johnny, he suffered horrific bullying and sexual abuse in the children's home he as dumped in, leading to another devastating resurgance of Kid Marvelman's powers.
The new Marvelman strips were sold to American publishers Eclipse, whereupon they gained the attention of Marvel Comics, who, as with DC, took exception at their use of the Marvel name. Eclipse changed Marvelman to Miracleman, with the rest of the new Marvel family changing in kind. There was also a version of Mary Marvel, named Miraclewoman, created when young girl Avril Lear was experimented upon to create a superpowered being in the nature of Marvelman/Miracleman. Moore left the comic and it was continued for some time by Neil Gaiman. After an unpleasant dispute over creators rights between various parties including Spawn creator Todd McFarlane, the collapse of Eclipse comics and his purchasing of their properties, and legal ramifications regarding the purchase of the original Marvelman material, Miracleman was scrapped. Just recently, however, Marvel have purchased the Marvelman back catalogue, although the reprinted Miracleman retains the Marvel-less name. A weird upshot of this is that Gaiman is now writing for Marvel and has sold them the rights to his Spawn character Angela, who is now part of the Guardians of the Galaxy and set to join the Avengers. Gaiman will be continuing the Miracleman story in new issues.
So, there are, currently, two characters called Captain Marvel. Carol Danvers is the Captain Marvel who belongs to Marvel Comics, used to be Ms. Marvel, and will star in the movie Captain Marvel. Billy Batson is the Captain Marvel who belongs to DC Comics, whose comic and upcoming movie are called Shazam! and who is officially called Shazam himself. Marvel comics still have a Ms. Marvel and sometimes a Marvel Girl, and while they now own and publish Marvelman, they're still marketing him as Miracleman. It's quite straightforward really.