The Secret History of Rock has a post and clips on the influence of the sword-and-sorcery (known as peplum) films, both European and American, and their aesthetic, contrasted with the stodginess of the 50s and 60s.
The formula was simple- an American muscleman playing a mythic hero (usually Hercules or one of his equivalents), an evil king or queen, a scheming priesthood bent on human sacrifice, a virtuous maiden in need of rescue and lots and lots of exposed Mediterranean flesh for every possible taste. To an America stuck in the corporate monotony of the Cold War, these films were like an explosion of pure id, an atavistic knife to the heart of a denatured West.
I would add a lot of slavery-type imagery: women imprisoned and auctioned, virtue in distress. This of course went into the Frank Frazetta-Boris Vallejo school of paperback cover art and heavy metal album covers, etc, etc.