The Children of the Emperor were a group of individuals who unknowingly served the Sith Emperor of the reconstituted Sith Empire as puppets and extensions of his will throughout the later years of the Great Galactic War and subsequent Cold War with the Republic. First created around 3678 BBY, the group consisted of individuals who had been brought before the Emperor as infants and imbued with a part of his own power, transforming them into his eyes and ears throughout the galaxy. By the time war broke out again around 3641 BBY, Children of the Emperor had unknowingly infiltrated the entire Republic, with members of the Jedi Order, Republic Military, Senate, and other organizations ready to activate and perform their master's will the moment he wished them to.
The Children were protected by the Emperor's First Son, a second personality embedded in the mind of Jedi Council member Syo Bakarn, who shielded his siblings from the Jedi's view and ensured that they remained undiscovered.
The Children of the Emperor came from many different worlds across the galaxy, consisting of individuals from a great number of species and backgrounds. As infants, they were stolen from their parents by the Servants of the Emperor's Hand and brought before the Emperor on Korriban. There, the children were subjected to various rituals and alchemical machinery in the depths of the Sith Academy while the Imperial Guard watched over them, and then they were brought before the Emperor himself.
The Emperor infused part of his strength within the infants, creating a mental link that could only be broken by an immense exertion of the light side of the Force.
The Emperor may have originally conceived the idea of the Children of the Emperor but it was the designs and inventions of the Sith Lord Darth Nul which made it possible earning her the mantle of "Mother" of the Children. Nul was tasked with finding the potential children, breaking them down, indoctrinating them to unconditionally serve the Emperor and finally imprinting them with the Emperor's power allowing him to freely control all Children as he pleased all the while the Children remain oblivious to what actually happened to them. At a later point, Darth Nul was dealt by the Emperor after having no more use of her and subsequently purged her records from the Sith Empire leaving the Emperor as the sole founder and "parent" of the Children.
The Children of the Emperor remained largely unknown to the galaxy throughout the Great Galactic War and part of the Cold War, even to some of the Children themselves. However, their existence was revealed to the Jedi Order by former Sith Lord Darth Sajar, and his information was confirmed when the Child Valis attempted to capture Kira Carsen. Carsen, a former Child who had fled the Empire as a young girl when she began to suspect the presence of the Emperor within her, was the Padawan of a powerful young Jedi Knight who managed to defeat Valis. After the fight, the Knight convinced Kira to tell the Council everything she knew about the group. Eventually, during the final battle against Darth Angral, Carsen was possessed by the Emperor, who attempted to use her to kill her Master but Carsen managed to sever the link between her in the Emperor, affirming her allegiance to the light side of the Force.
Sometime after the Dark Council learned of the Children's existence, a powerful Sith attempted to follow the Children and learn more about them. However, he was discovered by the First Son, and after undergoing surgeries and various treatments the Sith was reborn as Stark, a servant of the Children.
One Child named Augin Blaesus infiltrated the Rift Alliance, feeding information to Lord Kyrus, causing incidents to destabilize its relationship with the Republic. Eventually, they kidnapped King Sethun and Queen Nyscha of Sarkhai, but were both stopped by the Barsen'thor, the Warden of the Order. Before he died, Blaesus mentioned someone known as the First Son—the leader of the Children, who was shielding the other Children from the Jedi's sight.
As renewed war began between Republic and Empire, the Children began interfering with the Barsen'thor's efforts to raise an army to defend the Republic, recruiting Esh-kha and Voss but twice failed. Eventually, on Corellia, the Barsen'thor recovered a holorecording containing the identity of the First Son, who was none other than Syo Bakarn. Bakarn was a Jedi Master and longtime member of the Council, and he was not even actively aware that he was the First Son. Upon being exposed, the First Son assumed control of Bakarn's body and signaled the Children to capture the Guardian Holds. The Barsen'thor retook Guardian Holds Four and Six before pursuing Bakarn. Eventually confronting and dueling him, the Barsen'thor was able to defeat the First Son, allowing Bakarn to regain control and remove the shielding on the Children, enabling the Jedi to finally sense the hidden darkness within them through the Force so they could root them out.
Spirits of the dead Children arrive to assist in the Emperor's final defeat.
After the Hero of Tython had defeated the Emperor's Voice, his spirit returned to his original body and was sent into a deep slumber. In his slumber, the Emperor's injured mind reached out to his Children and began to whisper to them, raging at the Hero and issuing contradictory orders as his consciousness moved quickly from thought to thought. Some Children, such as Tannac, were able to block out the incoherent commands of their master, but others like Suri were almost driven mad by his rage and constantly shifting thoughts.
The Emperor, in the form of Valkorion, confided with the Outlander that he no longer needed the Children, the Hand and the Voice as he was now truly free from his "shackles" ever since the devastation on Ziost.
During the final confrontation with Tenebrae, the Children were among the spirits witnessing his final death.
Jedi Master Denolm Orr, a former Child, purposely came to Elom because he knew of Darth Nul's to the late Sith Emperor and her role in the creation of the Children. Prior to entering Nul's Temple, Orr made a holorecording revealing his past as a Child and his intention to purge the dark stain of the Children. The holorecording was later recovered by the Eternal Alliance later on.
Sana-Rae confirmed that with Tenebrae's final death, any and all influence the former Emperor had over the Children no longer existed. Former Child Kira Carsen offered her aid to the Alliance Commander in dealing with Darth Malgus and locating Sa'har Kateen.
- Star Wars: The Old Republic Encyclopedia