One issue later, Conan declared that she was his equal. That was the author’s ambition and, in Conan the Barbarian #23, their last book together, Thomas and Smith introduced Red Sonja as she was wielding a sword against guards, wearing a long-sleeved chain mail shirt. She could battle at his side and keep her feminine side. Red Sonja was to be a fierce warrior that could be Conan’s match. Howard’s short story “The Shadow of the Vulture.”
With artist Barry Windsor-Smith, Thomas created Red Sonja, a character that was loosely based on Red Sonya of Rogatino from Robert E. At the beginning of 1973, the Conan the Barbarian series was a success, and writer Roy Thomas wanted to expand Marvel’s sword and sorcery line with a spin-off title.