The Masters of the Universe toys and comics were developed by Mattel in the early 1980s. The characters inhabited a mythical land known as Eternia, and it soon became clear that the characters – including He-Man, She-Ra, and the arch enemy Skeletor – had even wider appeal than expected, and an animated television series was launched in 1982.

Made by Filmation, the series began life as commercials for the range of toys, but went on to become one of the most popular cartoons of the 1980s. The series also spawned a feature film in 1987.

The idea behind He-Man was to create an action figure range based on the stories of Conan the Barbarian by Robert E. Howard, and the 1982 film version starring Arnold Schwarzenegger. However, Mattel decided Conan was an unsuitable role model for small children and instead created the action figures hero He-man and the evil villain Skeletor. Mattel and Filmation wanted their toys and TV programmes to appeal to girls as well as boys, and so She-Ra: Princess of Power and He-Manā€™s long lost sister was introduced as the female superhero in 1985.

He-Man was so popular that in 1985 sales of the action figures grossed $400 million, beating even those of Barbie.