Almost did not get published. 

Herbert industriously reworked his two stories into a single, giant epic. The prevailing publishing wisdom of the time had it that SF readers liked their stories short. Dune (400 pages in its first hardcover edition, almost 900 in the paperback on my desk) was rejected by more than 20 houses before being accepted by Chilton, a Philadelphia operation known for trade and hobby magazines such as Motor Age, Jewelers’ Circular and the no-doubt-diverting Dry Goods Economist.

Though Dune won the Nebula and Hugo awards, the two most prestigious science fiction prizes, it was not an overnight commercial success. Its fanbase built through the 60s and 70s, circulating in squats, communes, labs and studios, anywhere where the idea of global transformation seemed attractive. Fifty years later it is considered by many to be the greatest novel in the SF canon, and has sold in millions around the world.

Dune is set in a far future, where warring noble houses are kept in line by a ruthless galactic emperor. As part of a Byzantine political intrigue, the noble duke Leto, head of the Homerically named House Atreides, is forced to move his household from their paradisiacal home planet of Caladan to the desert planet Arrakis, colloquially known as Dune. The climate on Dune is frighteningly hostile. Water is so scarce that whenever its inhabitants go outside, they must wear stillsuits, close-fitting garments that capture body moisture and recycle it for drinking.

Every fantasy reflects the place and time that produced it. 

If The Lord of the Rings is about the rise of fascism and the trauma of the second world war, and Game of Thrones, with its cynical realpolitik and cast of precarious, entrepreneurial characters is a fairytale of neoliberalism, then Dune is the paradigmatic fantasy of the Age of Aquarius. Its concerns – environmental stress, human potential, altered states of consciousness and the developing countries’ revolution against imperialism – are blended together into an era-defining vision of personal and cosmic transformation.

Books read differently as the world reforms itself around them, and the Dune of 2015 has geopolitical echoes that it didn’t in 1965, before the oil crisis and 9/11. Remember that European beach grass binding together those shifting dunes? Paul Atreides is a young white man who fulfils a persistent colonial fantasy, that of becoming a God-king to a tribal people. Herbert’s portrayal of the “Fremen” (the clue’s in the name) owes much to TE Lawrence and Wilfred Thesiger’s enthusiastic portrayals of the Bedouin of Arabia’s Empty Quarter. Fremen culture is described in words liberally cribbed from Arabic. They go on “razzia” raids, wear “aba” and “bourka” robes, fear a devil called “Shaitan” and so on. They are tough, proud and relatively egalitarian. The harshness of their environment has given them an ethic of fellowship and mutual aid. They are what Kipling would have termed “one of the martial races”: absolutely to be admired, possessing none of the negative “oriental” traits – deviousness, laziness and the like. They are, however, not carbon-copy Bedouin: Herbert freely mixes elements of Zen into their belief system, and also, intriguingly, suggests that their messianic eschatology – the sense in which they were “waiting” for Paul – may have been seeded in previous millennia by the Bene Gesserit order as part of its murky eugenic plans. Herbert, whose female characters are consistently strong and active, has also ditched the strict sexual divisions of actually existing Bedouin culture. Thus Fremen women do their share of fighting and fearlessly contradict their menfolk, though there is still a fair amount of child-bearing and housework to be done while the men are off riding worms.

What makes Dune more palatable than, say, the gruesome spectacle of a blonde-wigged Emilia Clarke carried aloft by ethnically indeterminate brown slaves in Game of Thrones, is the sincerity of Herbert’s identification with the Fremen. They are the moral centre of the book, not an ignorant mass to be civilised. Paul does not transform them in his image, but participates in their culture and is himself transformed into the prophet Muad’Dib. If Paul is one-part Lawrence of Arabia, leading his men on to Aqaba, he is also the Mahdi. Dune glosses this word as “in the Fremen messianic legend, The One Who Will Lead Us into Paradise”. In Islamic eschatology, the honorific Mahdi has a long and complex history. Various leaders have claimed or been given it. Most Shia identify the Mahdi with the 12th or Hidden Imam, who will imminently reveal himself and redeem the world. To the British, it will always be the name of the warrior prophet who swept through the Sudan in the 1880s, killing General Gordon on the steps of the palace in Khartoum and inspiring a thousand patriotic newspaper etchings. As Paul’s destiny becomes clear to him, he begins to have visions “of fanatic legions following the green and black banner of the Atreides, pillaging and burning across the universe in the name of their prophet Muad’Dib”. If Paul accepts this future, he will be responsible for “the jihad’s bloody swords”, unleashing a nomad war machine that will up-end the corrupt and oppressive rule of the emperor Shaddam IV (good) but will kill untold billions (not so good) in the process. In 2015, the story of a white prophet leading a blue-eyed brown-skinned horde of jihadis against a ruler called Shaddam produces a weird funhouse mirror effect, as if someone has jumbled up recent history and stuck the pieces back together in a different order.

Actually, the great Dune film did get made. Its name is Star Wars. 

In early drafts, this story of a desert planet, an evil emperor, and a boy with a galactic destiny also included warring noble houses and a princess guarding a shipment of something called “aura spice”. All manner of borrowings from Dune litter the Star Warsuniverse, from the Bene Gesserit-like mental powers of the Jedi to the mining and “moisture farming” on Tattooine. Herbert knew he’d been ripped off, and thought he saw the ideas of other SF writers in Lucas’s money-spinning franchise. He and a number of colleagues formed a joke organisation called the We’re Too Big to Sue George Lucas Society.

...

David Lynch’s film is actually much better than its terrible reputation, but Sting in a codpiece and a Toto soundtrack will never match the potential greatness of Jodorowsky’s unmade epic.

I thought Lucas' Star Wars was mostly ripping off the Hidden Fortress by Kurosawa?

I think most people could watch the two films back to back, and not recognize ANYTHING being ripped off.

Well, there's no accounting for the ignorance of most people nowadays... now is there:

The second major direction for Star Wars (used in the 1973 synopsis) was to use the Flash Gordon "vocabulary" to create an outer-space version of the Samurai films of Akira Kurosawa, in particularKakushi toride no san akunin (The Hidden Fortress, 1958), Tsubaki Sanjûrô (Sanjuro, 1962) and Yojimbo(which means "bodyguard," 1961). Joseph Campbell's The Hero With a Thousand Faces eventually gave Lucas a third and final major story direction, but many elements from Kurosawa's work remain, including the two bickering peasants (who evolved into the droids), elements of the Obi-Wan/Luke relationship and the queen who often switches places with her handmaiden. The Darth Vader-like evil general who has a change of heart at the end wears a kamon (commonly called simply a "mon", a Japanese family crest) that looks very similar to the Imperial Crest.

http://www.moongadget.com/origins/kurosawa.html