Gilbertus Albans [b. 185 BG) was a savage hrethgir toddler born among the slaves of Erasmus on his villa on Corrin; he was the subject of a second bet between Erasmus and Omnius about whether the way humans could function can be altered.
Omnius wagered that no matter how hard Erasmus tried, he would never turn a feral human child into a logical being. Erasmus took up the challenge with pleasure and chose the blonde-haired boy who appeared to be the wildest and most unkempt of all, in the animalistic lower social orders of the slave pens, and eventually educated the little human in the first mentat.
Gilbertus was born in the cruel slave pens in Erasmus' villa to a slave family. When Erasmus handpicked him, he spent the first few years drugging the boy and driving out his feral habits. Erasmus chose for him the high-sounding name 'Gilbertus Albans' that carried respectable and important tonalities so that it would evoke such behavior to the child.
After initially failing to make progress by using a system of benevolence and rewards, he switched to a system of strict supervision and punishment as well as behaviour-altering drugs. These alternate methods prove to be successful. By emulating Erasmus, whom he has come to consider his father, Albans becomes the first to display computer-like cognitive and calculation capacity on the level of thinking machines.
After that was accomplished, he then trained Gilbertus to think logically and organize his thoughts, in the same way a computer did. This allowed Gilbertus to remember everything, recite observations at a moment's notice, and rapidly perform computer-like calculations. He was also able to maintain several lines of thought and think in hyper speed.
To his own surprise, Erasmus also developed a fatherly attachment to the boy; when Gilbertus was about 20 years old, Erasmus performed a life-extension procedure on him without permission from Omnius. Because of Gilbertus' remarkable memory-organizational ability and capacity for logical thinking, Erasmus nicknamed him "Mentat", created from the words mentor, mentee and mentation, all coming from the Latin root for mind (mens).
Having already won the bet, Erasmus was determined to make him into the pinnacle of human ability. Soon Gilbertus was also doing physical exercises until his physique was as close to perfection as possible.
During the blockade following the Great Purge, Gilbertus enjoyed to spend time with clones of Serena Butler, while Erasmus attempted to reach the quality of the prototype. He was fond of one of them, and liked to talk with and teach her.
When the Battle of Corrin begun, Gilbertus felt bothered with the concept of the Bridge of Hrethgir; he didn't like the idea that Erasmus would be responsible for the deaths of millions. Therefore he programmed a trigger mechanism that would detonate the cargoes automatically, without Erasmus' input.
Erasmus then put the clone of Serena in one of the cargoes, and then Gilbertus in a safe basement. However Gilbertus realized the truth, and decided to join Serena as a slave. He then managed to contact Erasmus through a watcheye and tell him where he was. Erasmus then, to save his ward, reprogrammed and nullified the mechanism. The Army of Humanity fleet then passed through the Bridge without the expected losses.
Gilbertus returned to Erasmus with the help of a combat robot that Erasmus apprehended, but could not take Serena with him. When the end of the machines was close, he escaped with the memory core of Erasmus and joined a team of soldiers and Martyrists who devastated the structures.
Order of the Mentats
Presumably he found his way into the League of Nobles and trained other Mentats. After doing so, he needed temporary sanctuary with Bene Tleilax, who hoped to incorporate them into Tleilaxu hegemony. The Mentat's Order then spread into uncounted "seed schools". .
Behind the Scenes
Gilbertus Albans made his first appearance in The Dune Encyclopedia, and some time after he was quoted by Duncan Idaho in Chapterhouse: Dune. This fact placed Gilbertus Albans as the founder of the Mentats at Canon status, and his history, told us by the Encyclopedia, probably as truth. However it isn't known whether Albans was created by Frank Herbert and added later to his novel, or was he originally developed by Frank, who gave the information about Albans to be inserted in The Dune Encyclopedia.
Not much is known about the fate of Albans after the Battle of Corrin, and the origins and foundations of the order of the Mentats. Ten thousand years later, the Tleilaxu Kwisatz Haderach candidate, Thallo, told Marie Fenring that the Tleilaxu Masters had intentionally put cerebral matter of famous humans into his brain tissue to improve his cognitive reasoning. He told Marie that one such individual had been Gilbertus Albans, founder of the Mentat order.
Such information given in the Encyclopedia concerns a different version of Albans. That information can be combined with the above to give a possible full picture.