Jacen and his twin sister Jaina spent there early life hidden on unknown planets to protect them from harm by the Imperial Remnant. However, after several kidnapping attempts, their mother, Leia Organa Solo, New Republic Chief of State, decided they would be better off with their family on Coruscant. When his Uncle, Jedi Master Luke Skywalker, was attacked by the spirit of Sith Lord Exar Kun, he and his family went to Yavin 4 to help him recover. The only ones present who could see Luke's spirit were him and his sister and when Luke's body was attacked by predators, his spirit guided him in defending against them. Jacen succeeded, though he had never used a lightsaber in his life. In their early teens, the twins were sent to Luke's Jedi Academy, where they befriended Tenel Ka, a warrior woman from Dathomir, and Lowbacca, nephew of their father's close friend, Chewbacca. During his time there, Jacen developed an affinity with animals and the living Force. In fact, when he wasn't in lessons, he was often collecting some strange new creature to add to his private menagerie. At age fourteen, with the threat of the Second Imperium growing, Luke instructed Jacen Jaina, Tenel Ka, and Lowbacca in the construction of a Lightsaber. In a sparring exercise, Tenel Ka, who had sped through constructing her saber,  lost her arm when her blade gave out and Jacen's passed through it. Shocked and ashamed, he dedicated himself to Tenel Ka's recovery. Tenel Ka, however, got along fine without her arm, refusing to get a bio mechanical replacement. After taking her time building a second saber, she beat Jacen in a rematch. Together, the group defeated both the Second Imperium and the Anti-Human Diversity Alliance. During this time, Jacen tried to build a deeper bond with Tenel Ka, though their relationship never got farther than a close friendship. When Jacen was 16, the Yuuzhan Vong began invading the galaxy. Jacen and his siblings became pilots for a short while, he, his sister, and his younger brother Anakin all flew in the Battle of Dubrillion. He also rescued the beautiful Danni Quee from a Yuuzahn Vong prison on Helska 4. During a mission on Belkadan, he was captured by the Vongs. IT was only thanks to his uncle that he escaped. He took part in Corran Horn's slave extraction on Garqi and fought in defense of Ithor. During the Yuuzahn Vong attack on Fondor, Jacen persuaded Anakin not to use Centerpoint Station in an offensive strike and as a result indirectly killed many friendly soldiers. This caused a schism between them. At the battle of Duro, he recieved a vision through the Force telling him to stand firm, lest the invaders gain the upper hand. When Warmaster Tsavong Lah threatened his mother, he finally connected himself with the unifiying Force and met him head on, defeating him and earning himself a Yuuzahn Vong deathmark. Over the next year, he and his father and mother worked together to form the Great River, a safe route for hunted Jedi. When Han started using the Millenium Falcon to harass Yuuzahn Vong shippers, Jacen butted heads with him over the morality of the action. Jacen believed his brother was using the Force in a wasteful manner and, mainly to keep an eye on his brother, he accompanied him on a Jedi strike on the Yuuzahn Vong worldship near Myrkr. There, Anakin died in order to prevent the Yuuzahn Vong's genetic engineering of Jedi hunting beasts. Shortly after, Jaina fell to the dark side, though she soon went back to the light. Unable to escape, Jacen was captured. He met an enigmatic alien by the name of Vergere, a former Jedi who lived along side the Vong. He lied and said he excepted the Yuuzahn Vong philosophy. As a test of faith, the Vong brought him a captured Jedi and ordered him to kill him. Instead, Jacen and the Jedi teamed up and killed their captors. Jacen managed to escape. One of his first missions back with the New Republic was to travel to the living planet Zenoma Sekot, which Vergere said held the secret to defeating the Vong. Though it wasn't easy, they persuaded the planet to help them in their war. He accompanied his uncle on the final mission against the Yuuzahn Vong, during which he destroyed 15 slayers, some of the most dangerous soldiers in the known universe. After the war, Jacen set out in search of other Force users.