Kull was a proto-Conan that Howard wrote about before creating Conan and the whole Hyborian Age backdrop. This movie was apparantly supposed to start as a Conan movie, but when they couldn't get the rights to the character or something they switched it to Kull. It's alright, because Howard himself recycled some of his Kull material into Conan anyway.

Not the greatest film of all time by any stretch of the imagination, but still a lot of fun to watch.