Marvel Comics “Captain Marvel” first appeared in the late 1960’s, but he really hit his stride with a series of “stellar” adventures in the early 1970’s under the guidance of a hot new creator that took the alien character back to his roots in the stars.
Following his debut as the lead feature of Marvel Super-Heroes #12 (Dec. 1967), Captain Marvel, acquired his own title although the series met with lukewarm sales. The character was soon revamped by Roy Thomas and Gil Kane in issue #17, by merging the hero with new sidekick, Rick Jones via the Kree nega-bands. This change was meant to mold the character into a more science-fiction oriented version of Fawcett Comics' original Captain Marvel (whose trademark was acquired when the copyright on the original character was up for renewal). Both comics were about a young man who became a super-hero after being guided to a hidden installation, and who could then in a flash of energy become (or change places with) an adult super-hero in a predominantly red costume.
The revamp didn’t save the series and it was ultimately cancelled with issue #21. Thomas tied up several loose ends from the series in the pages of the Avengers comic book. When Mar-Vell was later revived in the early 1970s, plotter and artist Jim Starlin conceptually revamped the character, although Captain Marvel's appearance remained mostly unchanged. Mar-Vell became the "Protector of the Universe", appointed by the cosmic entity Eon.
However, his career was again cut short when he died from cancer in Marvel's first large-format graphic novel, The Death of Captain Marvel.