Mattel began developing their Masters of the Universe line of toys in the late 1970s. The first action figures went on sale in 1981, but a year prior to that, Mattel approached Filmation to help them market the new toys.

1982, Mattel had a legitimate success with their Masters of the Universe toys. However, they were getting a lot of phone calls and letters from confused parents and kids who had bought the action figures. Aside from He-Man, it was unclear who was a "good guy" and who was a "bad guy." Kids didn't know how to play with the toys. Prior to this, there was no "world" for the characters to inhabit. The action figures had names and little else. Enter Halperin who developed Eternia and Snake Mountain, as well as the official "Bad guy" counterpart to He-Man: Skeletor! 

In early 1983, with some backstory for the characters filled in and the toys a roaring success, Mattel made a deal with Filmation for an animated series.

The New adventures of He-man is developed and launched, although not well received. He-Man, legendary defender of the planet Eternia, has been summoned to the futuristic planet of Primus to defend the planet from the evil Mutants of the neighboring planet of Denebria. 

Masters of the Universe Modern Series is Launched accompanied by toys, known as Masters of the Universe 2002 by fans, this line of toys were more based around the animation of the show, leading to some awesome sculpts of the toys, especially Skeletor. Probably the cheaper of the toy lines since a lot of kids owned these ones and are more willing to sell, some of the main figures might be worth a pick up.

The collector exclusive market flourished with high-quality, pose-able toys from Japan. Celebrating the 25th anniversary, TMNT introduced cartoon-accurate, highly pose-able collector's editions. Concurrently, Mattel, through their subscription service "The Matty Collectors Club" and website, made a final push to revive the He-Man and The Masters of the Universe line for collectors.

After years of fan requests, Mattel answered with a limited run of Filmation-accurate toys through the "Club Greyskull" subscription service. Featuring iconic characters like He-Man and Skeletor, this final release of about 10 toys faithfully reproduced the beloved characters in cartoon-accurate form.

Super 7 came onto the scene and took the line over from the now bankrupt Matty Collectors company. Super 7 shifted towards collectors by recreating the 1982 line with Filmation-accurate coloring. Instantly selling out, these figures are now nearly impossible to find at reasonable prices. Still, it fulfilled the demand for the original toy look.