Galen Marek, codenamed Starkiller, was a human male Force-sensitive who served as the personal assassin of the Sith Lord Darth Vader, who trained Starkiller as his secret apprentice—but came to the light side shortly before his death. Marek was the son of two Jedi Knights, Kento and Mallie Marek, born on the Wookiee homeworld of Kashyyyk in the aftermath of the Clone Wars. Following his mother's death, Kashyyyk was invaded by the Galactic Empire as a target of the Great Jedi Purge, Kento was confronted and slain in a lightsaber duel by the Dark Lord of the Sith, who discovered the fugitive Jedi's son in the process. Gauging the orphan's raw strength in the Force, Vader abducted and ultimately raised Marek, who became Starkiller, to embrace the dark side of the Force.
In time Marek forgot his past and even his birth name, having been taken from his home as a child by the Dark Lord. Though trained in the ways of the Sith, the Rule of Two dictated that there could only be two Sith at a time, and therefore Starkiller could not consider himself a true Sith while his master was still apprenticed to Darth Sidious. As such, Vader kept his existence a secret, bestowing to him the call sign "Starkiller." and was utilized as a hidden agent of the Empire, dispatched to deal with problematic individuals in the Empire while he trained. For years, Starkiller aspired to truly become a Dark Lord of the Sith, believing it was his destiny to help Vader overthrow Sidious and usurp his throne as Galactic Emperor. As his training neared completion, Starkiller was formally acknowledged as an apprentice by Vader after surviving his trials, and was ordered by Vader to kill the few remaining members of the fallen Jedi Order—specifically the Jedi Masters Rahm Kota, Kazdan Paratus, and Shaak Ti.
The secret apprentice completed his missions, prevailing against his more experienced targets, only to be betrayed by his master after the Emperor confronted them. Stunned by this turn of events, Starkiller nevertheless remained loyal to Vader, and began fomenting a rebellion against the reign of the Galactic Empire as part of his master's plan to depose Sidious. The mission was another ruse, however. After the apprentice convinced Bail Prestor Organa, Garm Bel Iblis, and Mon Mothma to join him, Vader had the senators arrested and left Marek for dead, betraying him once more, revealing he was but a tool in a plot by Sidious and Vader to crush the rebellion before it even began, however he lived. Resolving to rescue his allies, he managed to infiltrate the Death Star before the Emperor could execute them. Although he was killed in the ensuing battle aboard the battlestation, the senators were able to escape with the help of Markek's companions, PROXY and Juno Eclipse. As a result of the apprentice's actions, the Alliance to Restore the Republic was formed, uniting malcontents across the galaxy under the symbol of Marek's family.
