Legends of Dune refers to a trilogy of full-length novels and a series of short stories by Brian Herbert and Kevin J. Anderson. They are a prequel trilogy to the Prelude to Dune series and revolve around the Butlerian Jihad -the war against the thinking machines.
In the Old Empire humans had become complacent and reliant on machines to run their society. A small group of individuals took control of the Old Empire's computer systems and used the machines humanity had become dependent on to conquer them. Calling themselves "Titans" humanity's new rulers had their brains removed and placed in robotic bodies in order to prolong their lives and rule, therefore becoming cymeks. As time passed the Titans associated themselves less with humanity and became more oppressive. Billions died under their rule.
After several centuries the Titan Xerxes became complacent and dependent on an artificial intelligence. After turning against Xerxes, the AI, calling itself Omnius, spread to the worlds of the other Titans and quickly defeated them. Because of its programming Omnius was unable to harm the Titans but instead incorporated them into its Empire, the Synchronized Worlds.
When the Titans had initially seized power a group of humans formed the "League of Nobles" to resist them. The League of Nobles would continue its resistance against Omnius for over a thousand years before the events of the books.
The universe at the time of Legends of Dune consists of essentially three groups of populated planets: League Worlds, Synchronized Worlds and Unallied Planets.
- Hunting Harkonnens - a short story set before the series
- Whipping Mek - a short story
- The Faces of a Martyr - a short story
The prequels are intended to expand the Dune canon. However due to the diversity of themes and several alleged inconsistencies, they are rejected by some fans. As a result, information from these novels and stories is considered Expanded Dune on the Dune Wiki.
According to Willis McNelly, in a letter written by himself, Herbert and Anderson, the LoD trilogy is an actual expansion of the Dune universe, unlike The Dune Encyclopedia, another Expanded Dune publication, which "reflects an alternate 'DUNE universe'".