Red Sonja was created by writer Roy Thomas and artist Barry Windsor-Smith for Marvel Comics in 1973, partially based on Red Sonya, a female swashbuckler from "The Shadow of the Vulture".
Red Sonja debuted in Marvel's Conan the Barbarian #23 (1973). Thomas created a new origin story and transposed the timeline from the 16th century of Howard's original Red Sonya to the Hyborian Age, another Howard creation, to have Sonja interact with Conan the Barbarian. In 1975, Marvel Comics published the first issue of Marvel Feature vol. 2 that was headlined by Red Sonja. The seven issues featuring Red Sonja were written by Roy Thomas and Bruce Jones. From #2 on, Frank Thorne provided the art for the series. In 1977, the character received her own, self-titled series. The fifteen issues of Red Sonja were written by Clair Noto and Thomas, with art by Frank Thorne (#1–11), and later on, pencils by John Buscema (#12–13, 15) and Sal Buscema (#14), who were inked by Joe Rubinstein, Al Milgrom and Tony De Zuniga.
Red Sonja's origin story was told in the story "The Day of the Sword" in the Marvel magazine Kull and the Barbarians #3 (1975), written by Roy Thomas and Doug Moench and illustrated by Howard Chaykin. The same story was later redrawn by Dick Giordano and Terry Austin and published in the magazine The Savage Sword of Conan #78 (July 1982). In this version, Red Sonja lives with her family in the Western Hyrkanian steppes. When she is 21, a group of mercenaries kills her family and burns down their house. Sonja attempts to defend herself, but cannot lift her brother's sword. She is raped by the leader of the group. After managing to escape from the burning farm, the red goddess Scáthach appears to her and gives her incredible fighting skills, on the condition on never allow a man to love her, unless he defeats her in fair combat. In the story "Sword of the She-Devil" Marvel Team-Up #79 (December 1979), Red Sonja is reborn in the present-day of Earth-616 when her sword is found by her descendant/reincarnation Mary Jane "MJ" Watson (love interest of Peter Parker / Spider-Man).
In 1983, Marvel Comics published a second Red Sonja series, a two-issue story written by Christy Marx and Roy Thomas, with art by Tony DeZuniga and Ernie Colón. The story also featured an appearance by the Robert E. Howard heroine Valeria.
That same year, Marvel launched a third series, running for thirteen issues. Writers included Tom DeFalco, Bill Mantlo, and Louise Simonson, with art by Mary Wilshire, Pat Broderick, and Rudy Nebres, among others.