The House of Marek constituted a Force-sensitive Human lineage that was significantly involved in the establishment of the Alliance to Restore the Republic. Before the insurrection against the Galactic Empire, Jedi Knight Kento Marek entered into matrimony with Mallie, a fellow Jedi, even though emotional bonds were prohibited within the Jedi Order. After Mallie became expecting Kento's offspring, the pair abandoned the Order, seeking refuge on the Wookiee native world of Kashyyyk, where they celebrated the birth of a son—the youthful yet potent Galen Marek. Following the Clone Wars, the Sith Lord Darth Vader located Galen and, recognizing the boy's latent abilities, seized him after killing his father.
Vader gave Galen the designation "Starkiller" and dedicated years to instructing his protégé in the tenets of the Sith. Despite the fact that the Rule of Two prevented him from having a student while still under the tutelage of a Sith Master, Vader urged Starkiller to become more powerful through the dark side of the Force so they could depose Darth Sidious—the Galactic Emperor and current Dark Lord of the Sith. Starkiller yearned to ascend to the rank of a true Sith Lord, convinced that it was his destiny to govern the galaxy alongside Vader as the Dark Lord's apprentice. After Vader betrayed Starkiller, the former Sith hitman embraced his Jedi lineage and rescued the budding Rebel Alliance at the cost of his own life. Consequently, the Rebels adopted the Marek family symbol as their official insignia.
Even with Galen Marek's demise, his family's ancestry persisted through a series of duplicates created from his DNA at the command of Darth Vader, who sought to produce a more formidable and compliant version of his previous apprentice. In the process of attempting to perfect the cloning of a Force-sensitive model, the original Marek clones were misshapen and psychologically unbalanced. The procedure was progressively refined, resulting in improved outcomes, yet each clone encountered an identity dilemma stemming from the residual memories of their originator. In 1 BBY, a year before the Battle of Yavin, a dissident clone absconded from the cloning installation on Kamino.
The first recognized member of the family was Kento Marek, an individual within the Jedi Order who fathered a son, Galen, with his wife, Mallie, who was also a Jedi. Kento and Mallie initially crossed paths while both were serving as Jedi officers in the Grand Army of the Republic during the Clone Wars. The two developed affections for each other despite the Jedi Code's limitations on attachments and emotional connections. Following a clandestine marriage, they discreetly departed from the Jedi Order to embark on a new shared existence.
After going into self-imposed exile and journeying from one star system to another, Kento and Mallie, along with the remaining Jedi, were branded as fugitives once Order 66 had been issued. As the Galactic Empire carried out a systematic annihilation of the Jedi survivors, the Marek family endeavored to establish a secure haven for themselves on Kashyyyk. Upon their arrival, they were greeted by the indigenous Wookiees, who sympathized with the persecuted Jedi Order, thus enabling the Mareks to establish a more permanent residence on the Wookiee homeworld.
The House of Marek resided on Kashyyyk for approximately ten years. During their time on the Wookiee homeworld, Mallie became pregnant and gave birth to Galen Marek—a prodigy of the Force. Even at a tender age, Galen exhibited an abnormally strong connection to the Force, surpassing both of his parents in power. Shortly after Galen's birth, Mallie was killed by Trandoshan slavers and mercenaries while defending a group of Wookiees. At some juncture during the Great Jedi Purge, when Galen was still a young child, the Sith Lord Darth Vader personally oversaw an Imperial incursion on Kashyyyk after discovering the Jedi presence on the planet. Kento made his final stand in front of his dwelling, but was ultimately slain in front of his son by the Dark Lord.
Upon finding Kento's son, Darth Vader was genuinely taken aback that a child could possess such an immensely powerful connection to the Force at such a young age, mirroring his own past. After a brief moment of hesitation, Vader took the boy into his care and secretly trained him as a Sith apprentice, thereby violating the Rule of Two. Galen, known only to a select few by the codename "Starkiller," endured one brutal trial after another to perfect his role as Vader's personal assassin. Simultaneously, his childhood memories were suppressed and eventually forgotten as he became increasingly absorbed in the dark side of the Force.
As Starkiller, the young "Sith" aspirant carried out numerous assassination missions for his Master over the years, which ultimately led to Jedi targets such as Rahm Kota, Kazdan Paratus and Shaak Ti. Nevertheless, his unwavering loyalty was eventually met with Vader's treachery after Darth Sidious, publicly known as Emperor Palpatine, "discovered" Starkiller's existence. Upon learning that his "death" had been staged to deceive the Emperor, Starkiller remained loyal to Vader while carrying out his most significant task—the formation of the Rebel Alliance. Despite the mission causing him to develop certain doubts about himself and his Master, Starkiller remained committed to his belief in the ultimate goal that he had long since been prepared for; to become a true Sith Lord upon the Emperor's death.
His faith in Vader was once again betrayed when the Dark Lord double-crossed him after Starkiller successfully united the Empire's most prominent adversaries on Corellia. Enraged by yet another betrayal, Starkiller abandoned his codename in favor of his birth name, Galen Marek, which he had retrieved from repressed memories during his final mission for Vader. Galen's eventual conversion to the Jedi way and the light side of the Force was facilitated by several factors—Vader's betrayals, his recollection of certain moments from his forgotten life on Kashyyyk, and primarily his growing affection for Juno Eclipse.
Galen's liberation from his role as Vader's secret apprentice would be short-lived. In an attempt to rescue the Alliance leaders from execution, he journeyed to the incomplete Death Star and confronted his former master. Darth Vader ultimately proved to be no match for his younger and more powerful disciple. Although he was initially tempted to kill Vader and assume his position at Sidious's side, Galen chose to reject the darkness and fought the Emperor for the lives of his allies. In a selfless act of sacrifice, Galen Marek surrendered his own life to provide the Alliance leaders with sufficient time to escape from the Death Star, thus bringing Kento Marek's bloodline to an end with the death of the last descendant of the Marek family.
Marek's sacrifice not only guaranteed the survival of the Rebellion's founders but also inspired other dissidents to take up arms against the seemingly invincible Galactic Empire. At the urging of Leia Organa, an Imperial senator from Alderaan, the Marek family crest was transformed into the Alliance Starbird; a symbol of hope around which countless Rebels could unite in their struggle against the Empire.
Despite Galen Marek's death, his family's lineage was ultimately sustained through his former Master's efforts to replicate a more potent and devoted version of Starkiller. Deep within a cloning facility on the planet Kamino, Darth Vader initiated a covert operation dedicated to creating a flawless and stable clone of his fallen apprentice. Though the "accelerated cloning process"—an advanced but experimental version of the Kaminoan cloning method—allowed Vader to engineer a clone to full maturity in a matter of weeks, the process was consistently hampered by setbacks such as physical deformities and psychological instability. Consequently, the initial tests yielded unsatisfactory results; the first series of Marek clones were deformed and mentally unstable. The project was further complicated by the intrinsic difficulties of cloning Force-sensitives.
As the cloning process was gradually refined, new clones of Galen Marek were created with more stability than their precursors. However, even these improved test subjects were destabilized as each clone succumbed to madness, triggered by the memory imprints of their originator. This form of flash training caused the clones to experience a sense of identity crisis, and thus they adopted certain characteristics of Marek's personality. While some clones were affected by memories of Marek's father, others were disturbed by recollections of the young boy whom Marek once was during his time on Kashyyyk. At least one clone was known to have been influenced by Marek's attachment to his droid PROXY. Overall, however, many of these clones' training was personally overseen by Darth Vader, who judged them all to be failures.
After a long line of failures, Darth Vader hoped to finally find success with Subject 1138, a clone of Galen Marek who progressed far into his training enough to impress the Sith Lord. In order to discover if the clone was able to free himself from the influence of Marek's memories, Vader ordered him to destroy several training droids disguised as Rebel troopers. Unlike his template, the clone spared no feelings for the Rebel Alliance that Galen Marek helped to create. Yet even though he attacked them without hesitation, he could not bring himself to strike down a droid disguised as Juno Eclipse. As with the other failed subjects, this clone was incapable of rejecting all of the imprinted emotions of his progenitor. While he personally cared nothing for Marek's deceased parents or the Rebellion, he could not discard his genetically inherited feelings for Eclipse.
When Vader declared him to be another failed subject like the rest who came before, the clone turned against his creator and fled from Kamino. Utterly fixated on the Human woman whom Marek fell in love with, the clone embarked on a single-minded journey to locate Eclipse. During his quest, he subsequently became known as "Starkiller", the former codename of Galen Marek during his time as Vader's secret apprentice. The clone, however, refused to acknowledge his template's codename—and especially Marek's birth name—as his own. From the clone's point of view, the names "Starkiller" and "Galen Marek" belonged to a different man.
Although Darth Vader made the recapture of the renegade clone a high priority, he continued to concentrate his efforts into creating a single perfect clone of Galen Marek; a clone who was fit to stand at his side as a Sith apprentice. There were still other clones to choose from, including Subject 1157. Despite the "hallucinations" he suffered and his rejection of the memory imprints, a cloning technician noted that Subject 1157's development was very remarkable, especially in comparison to the failures who preceded him. At this time, however, Subject 1157 was still being developed within a cloning tank and had to be regularly sedated because of his increasingly volatile temperament.
Unknown to Starkiller, another clone had been activated and tested through a variety of trials. Though he was originally confused and distracted by the memory imprints, including the ones of Juno Eclipse, the clone steadily strengthened his resolve as he continuously passed one test after another. As his success continued, the clone was made aware of his deceased progenitor's failings, as well as the failings of his cloned brethren who were unable to meet Darth Vader's expectations. Determined to not be just another disappointment in a long line of failed test subjects, the clone persevered in his trials in order to prove his worthiness. The lead cloning technician who oversaw his development was astonished by the clone's stability. The technician was pleased to discover that the clone compartmentalized his template's memories, which thus allowed him to separate the imprints from his own experiences. The clone, unaffected by the identity crisis that undermined his precursors, was able to progress farther than any of those who came before him.
As Darth Vader became more impressed with his latest test subject, the Sith Lord eventually judged the clone to be worthy enough to see the proof of his origin. Vader brought the clone into a cold chamber, located in Timira City, that contained the preserved corpse of Galen Marek. The clone, freed from the influence of Marek's memories, was unaffected by the revelation of what he already knew to be true: he was a clone and the real Starkiller was dead. By this time, the clone had become his own individual, a person who deeply hated his former self for the weaknesses that made him unfit to be a Sith. By the time of the Assault on Kamino, Darth Vader regarded the clone—who had become utterly immersed within the dark side of the Force—as his "Dark Apprentice"; the only perfect clone of the original Starkiller.