Prequel to the MAIN Dune Series.
Also known as the House Trilogy, the Prelude to Dune series tells of events in the years before the classic Dune sequence.
The mames of the books are pretty "self Explanatory"
Still even if these stories do occur BEFORE the main Dune story these books SHOULD be read after that to understand these books.
It is also the order the author(s) told the story.



Book 1 House Artreides
The novel begins 35 years before the events of the original Dune. 
Three interconnected narratives revolve around heir-apparent to House Atreides Leto, acting governor of Arrakis Baron Vladimir Harkonnen, and Imperial Crown Prince Shaddam. 
Side plots involve a young Duncan Idaho escaping enslavement at the hands of House Harkonnen, a young planetologist Pardot Kynes befriending the Fremen native to Arrakis, and the Bene Gesserit's troubles producing a child from the union between the Reverend Mother Gaius Helen Mohiam and Vladimir Harkonnen.



Book 2 House Harkonnen
Eighteen years have passed since Shaddam IV succeeded his father as Padishah Emperor of the Known Universe. 
However, his rule is precarious as his wife Anirul has been instructed by her Bene Gesserit sisterhood to bear him only daughters. 
Shaddam's authority is also challenged by the powerful House Harkonnen, whose illegal stock-piling of melange is of great concern to the Emperor. 
In order to monopolize the spice, Shaddam and his trusted advisor and friend, Count Fenring, plan to synthesize the substance with the help of Hidar Fen Ajidica, a Tleilaxu Master Researcher. Ajidica sets up laboratories to accomplish this purpose on the newly conquered planet of Ix, formerly the home of House Vernius. 
By the end of the novel, Ajidica tells Fenring that the manufacture of synthetic spice has been a success, although the validity of his claim is highly dubious.



Book 3 House Corrino
One year after the War of Assassins, Duke Leto Atreides sponsors an assault on Ix to reclaim the planet for House Vernius, while his concubine Jessica is pregnant with his son. 
Emperor Shaddam IV commences his Great Spice War to create a dependency on his soon-to-be-released synthetic melange, ajidamal. 
The Bene Gesserit eagerly await the birth of the Kwisatz Haderach's mother by Jessica; little do they know that things are not going to turn out exactly how they intend.