After living with the Fremen for several years, she was present in the palace in Arrakeen when her brother and his forces successfully conquered the combined forces of the Emperor's Sardaukar and House Harkonnen. During the invasion she poisoned Baron Vladimir Harkonnen with a Gom Jabbar.
Establishing Her Rule
Later, upon the death of Paul, and with his children Leto and Ghanima still too young to effectively rule, Alia went from being a Princess to being the Imperial Regent of the Atreides Empire. She was corrupted by power and established a cult of personality, using rich trappings and grandiose titles such as the Mahdinate to build considerable political weight.
Shortly thereafter, Alia fell fully into Abomination, and was secretly tormented by the living personalities of countless ancestors. Chief among these was the personality of Vladimir Harkonnen, who sought to use his granddaughter as a tool to reclaim power from beyond the grave.
Alia had few close, genuine relationships, largely due to her mentally and emotionally imbalanced state. Her relationship with her mother was strained at best, and simmered with deep resentment. And her interaction with Fremen was tarnished at an early age by their fear of her abilities and knowledge.
Though she loved and admired Paul, her brother, she also partly resented his influence. And her love for the original Duncan Idaho ghola was ultimately destroyed by a casual affair with Javid, one of her priests who secretly served the Fremen insurgents who plotted against her.
During the same years in which she held herself aloof from family and friends, Alia indulged in massive doses of melange, ostensibly for the purpose of broadening her prescient vision. However, Alia lacked her brother's prescient ability, and the spice trance most often failed her. The same drug which had initially keyed her sensitivity to her ancestral voices could be depended upon to keep those same voices from becoming blurred or unavailable. As a result, Alia's heavy melange consumption became a means of maintaining contact with her internal advisors and gave them power.
Alia's actions during her Regency were those of a power-hungry woman aided by the memories of generations of ambitious rulers and princelings. Her every manoeuvre, including her marriage to the first Duncan Idaho ghola, was seen as having been performed in order to solidify her own position, and her manipulation of the children in whose names she ruled was also considered a devious maneuver. Not content with having destroyed herself, she set about to lead her niece and nephew into similarly destructive ways. Since the most direct way of achieving this goal involved the children's becoming enmeshed in their ancestral memories, Alia continually tried to interest them in the spice trance.
thumb|left|Leto's return and Alia's suicide. Alia ordered the assassination of The Preacher, despite knowing it was her beloved brother. Upon Leto's return from the desert, he gave her a choice, Trial of Possession or suicide. Realising that she would not pass the Trial, Alia threw herself from a high window to her death, a death that was witnessed by her mother Jessica, the Atreides twins, and Farad'n Corrino.
Had it not been for her death, Alia could have continued to rule for several centuries by regenerating her cellular structure. According to Fremen tradition, as with all Abominations the only cure was death.
The impact of Alia's religious powerbase was long-lived. Many considered her a revered figure for several hundreds of years after her death. In the months prior to Leto II's death, a cult of Alia was discovered on Giedi Prime by Duncan Idaho's agents. Ultimately however, Alia's influence vanished after Leto's death, some three and a half thousand years after her own death.