(For the record: Norton has spoken on-the-record to express her dissatisfaction with her novel being so closely associated to the first film. In fact, Norton demanded that her name be removed from the original prints, even though the film's director has spoken fondly about his inspiration from her novels. Ouch.)
Director Don Coscarelli worked on the screenplay to adapt the ideas from the Norton book for the silver screen. Marc Singer was cast as the hunky lead, and he was joined by John Amos, Tanya Roberts, Rip Torn, and Rod Loomis in key roles. Here's the film's plot summary as provided by IMDB.com:
"A sword-and-sorcery fantasy about a young man's search for revenge. Armed with supernatural powers, the handsome hero and his animal allies wage war against marauding forces."
Though I've read that, initially, The Beastmaster really only enjoyed modest success at the U.S. box office, the film surprisingly developed a strong cult following over the years from TV and pay cable broadcasts as well as a healthy interest from the home video crowd.
I guess it's safe to say that there's no keeping a good BeastMaster down.