The Titans are a group of fictional characters in the Legends of Dune series of novels, written by Brian Herbert and Kevin J. Anderson and set in the Dune universe created by Frank Herbert. The twenty Titans took over the Old Empire, a millennium or so before the Butlerian Jihad, and most notably include Agamemnon, Ajax, Barbarossa, Dante, Hecate, Juno, Tlaloc and Xerxes. Of the remaining 12 Titans, only Alexander and Tamerlane are explicitly named.
After their leader, Tlaloc, was killed in a freak accident about ten years into their reign, the Titans came to the realization that not only were their human bodies fragile but their lifespans were limited; thus, they soon sought new ways in which to continue their rule. Juno was the one to discover a way to achieve this after speaking with the Cogitor Eklo, a disembodied brain in a canister with a perpetually living and aware consciousness. Agamemnon was the first to attempt this transition into what would be called cymeks; through the use of specialized interfaces, his brain in the canister was installed inside a large walking machine body from which he might continue his rule indefinitely. These fearsome, weaponized bodies would make the Titans virtually unstoppable. Having pushed to the very farthest limits of artificial intelligence, their machines ran their empire for them almost completely, allowing the Titans leave to enjoy all the luxuries they desired (the nature of which are left to the reader's imagination, although it is revealed that the Titans were able to have some type of sexual activity, at least with other cymeks).
Their rule carried on in this form for about 100 years and was known as the Time of the Titans. A handful of human worlds on the fringes of known space remained independent, and several hrethgir (slave) rebellions erupted, with Alexander and Tamerlane slain by the rebels, but neither of these threats proved fatal to the Titans' continued rule. Ironically, the Time of the Titans would instead come to an end through the same chain of events that had catapulted them into power. Xerxes gave his AI attendant program a little too much autonomy (that he might work even less), repeating the very mistake that the Titans had despised their fellow humans for. The result was nearly instantaneous; the machines rose up again, this time against Xerxes and under the control of this first fully functional artificial intelligence (humanity itself had been sufficiently cowed under the rule of the Titans and so were spared the brunt of this second machine revolution). Taking the name Omnius for itself, this new consciousness overtook the network of all interconnected thinking machines in an instant. It then spread itself outwards, assuming control instantly as it reached each new world before any alarm could be raised, overthrowing the ruling Titans world by world. Fortunately for the Titans, Barbarossa had possessed the foresight to ensure that the machines were incapable of directly harming their now-former rulers, and thus their continued existence was guaranteed.
For over 900 years the Titans lived in perpetual servitude to Omnius, slowly going insane, knowing that their every move was observed everywhere they went except the very darkest reaches of space — the only place where they might plot to overthrow Omnius. Their cruelty in the treatment of humans was unspeakable, both toward the enemies of the Evermind and to those who had already been conquered. In special purpose-built cymek bodies, the Titans were an immensely powerful force on the battlefield and charged at the front of Omnius' thinking machine armies in clashes with the last remaining free human worlds. When not engaged in battle, they commissioned the design and construction of hundreds of colossal monuments to themselves throughout the Synchronized Worlds, using the humans as slave laborers.
Through the use of preserved reproductive material (frozen sperm) and selective breeding with slave women, the Titan Agamemnon was able to produce offspring; however, his contempt for humans and his incredibly high standards often led to the destruction of said offspring. One of these, Vorian Atreides, thirteenth son of Agamemnon, survived to become instrumental in the eventual overthrow of the thinking machines, and also responsible for the death of his father.
After Vorian joined the Army of the Jihad, Agamemnon decided along with the remaining Titans to rebel against Omnius. When Agamemnon was holed up on Hessra in 88 B.G., Vorian tricked Agamemnon into trusting him and then pushed him over the ledge of a window to his death.
Agamemnon's wife/lover in both human and cymek form was the Titan Juno.
Ajax's lover before the Time of Titans was Hecate, who also underwent the cymek conversion surgery. Later, realizing his brutal, thuggish nature, Hecate abandoned Ajax and the other Titans.
Ajax eventually met his end at the hands of Iblis Ginjo, soon to become Grand Patriarch. The robot Erasmus, as part of a challenge with the Omnius Evermind on Earth to prove that no human could ever be trusted wholly, had dispatched secret messages to selected slave bosses around the planet, suggesting there was an organized movement against the thinking machines. Iblis believed there was a greater human resistance, and so planned the eventual hrethgir (derogatory term for humans) revolt on Earth. The catalyst came with the murder of Manion Butler, (or Manion the Innocent, as he later became known,) son of Serena Butler and Xavier Harkonnen. Seeing the terrible death of baby Manion, and the distraught Serena daring to attack Erasmus with her bare hands, the humans rose up, and Iblis put his plans into motion.
Concealed behind a large frieze depicting the Titans' conquests (ordered built by Ajax himself), Iblis and his loyal slave crews had concealed old-fashioned rocket and other explosive weapons. When Ajax learned of the revolt, he immediately went to work attempting to stamp out the resistance. Iblis fired his concealed rockets, disabling one of the Titan's legs, immobilizing him. Ajax was felled, and swamped by slaves. Despite the slaves being killed in droves, Ajax's brain preservation canister was eventually smashed, and his ancient brain mashed into pulp.
Barbarossa perished during the liberation of Giedi Prime when he along with his neo-cymeks were obliterated by a mental shock wave unleashed by a Rossak Sorceress named Heoma.
Eventually, when the Butlerian Jihad was at its fullest, Hecate returned in a specially-designed, asteroid-shaped ship. She met with her former lover's killer, Grand Patriarch Iblis Ginjo, and pledged her support to the Jihad in fighting her former associates and the computer evermind, Omnius. The Grand Patriarch convinced Hecate to keep her involvement a secret from the League of Nobles at large, as a cymek's help would bring the Jihad and its fanatical following (and Ginjo's power base), crashing down around them.
Hecate performed notable strides forward on behalf of the Jihad, delivering a nuclear warhead deep into the Synchronized Worlds on Bela Tegeuse, wiping out the evermind incarnation there. She also assisted in the retaking of Xerxes' homeworld, Ix. Unfortunately, the League was too enamored with bickering and petty issues, and could not prioritize, meaning these opportunities were blithely wasted. General Agamemnon and the remaining Titans set up Bela Tegeuse as the seat for their new empire having rebelled against Omnius.
Hecate eventually met her end in a tragic misunderstanding. The businessman Aurelius Venport and Supreme Sorceress Zufa Cenva (his mother-in-law and former lover), were traveling back to the shipyards of Kolhar, where Norma Cenva was creating the very first spacefolding vessels. They had just finished negotiating a deal with priestess Serena Butler on Salusa Secundus that would eventually see the Spacing Guild claiming all rights to a universe-wide monopoly of space travel.
They were ambushed by the neo-cymek Beowulf and his legion, who had learned of the Holtzmann engines from their spy, Yorek Thurr. They wished to obtain it for Agammemnon's empire. Just as it looked as though Aurelius and Zufa would have to obliterate the ship, Hecate's asteroid ship arrived, destroying the cymeks and severely damaging Beowulf.
As Hecate attempted to enter Venport's ship, Aurelius and Zufa merely saw a Titan — an enemy — as Ginjo's pact with Hecate was still a closely guarded secret. Hecate entered, announcing herself "I am the Titan Hecate ..." This was all Zufa Cenva needed to hear; she unleashed the full fury of her telepathic powers, disintegrating Hecate's brain, her own, and that of Aurelius.
In the Time of the Titans, Xerxes was the last of his kind to undergo conversion into a cymek. He was responsible for the eventual downfall of their hundred year regime, allowing his computerized attendant too much control over the systems of his decadent palace. The attendant, which came to call itself Omnius, took over the Titans' empire as a direct result of Xerxes' action.
Xerxes served as a regent and general in service of Omnius' Synchronized empire. In space combat he utilized a massive robotic body that resembled an enormous and heavily armed spacegoing bird of prey. He eventually met his downfall when, during the brutal torture of Norma Cenva, he inadvertently awakened her latent psychic abilities. She then obliterated his brain and those of several of his lesser cymeks with a powerful psychic shockwave.