The Jaeger family (イェーガー家 Yēgā-ke?) is an Eldian family that lives both inside and outside the Walls. Most of them live outside, in the Liberio internment zone. One of them, Grisha Jaeger, went inside and started a new family in Shiganshina District on the southern edge of Wall Maria.
The Jaeger family were descendants of Eldians who stayed in Marley after the Great Titan War. They lived in the internment zone in Liberio, where people like them were forced to stay by the Marleyan government.
One day, Grisha and his little sister Fay left the ghetto without permission in order to follow an airship flying in the sky. They crossed a town before eventually reaching their goal. As they watched the airship landing, two Marley Public Security officers noticed them and asked them if they had an exit permit to leave the Liberio internment zone. Grisha admitted they did not and chose to take his sister's punishment with his. One of them led Fay away while the second beat Grisha. When he got back home, Fay was not there. The two officers Grisha met earlier came and explained to the parents they found their daughter's body. In addition, they scolded them for their children's behavior and advised them to teach Grisha their ancestors' history, which Grisha's father did. Years later, Grisha followed in his father's footsteps and became a doctor. He joined the Restorationists group after having heard the circumstances of his sister's death. Through his new activities, he met a young woman of the royal family named Dina Fritz. They got married and had a son they named Zeke.
A few years later, the Marley government announced they were at war with Paradis Island and were looking for Eldian children to become part of the army and host the Power of the Titans. Grisha found a great opportunity for the Restorationists and decided to make his son one of the chosen children. Thus he asked Zeke to become a double agent, pretending to be loyal to Marley whilst serving the cause of the Restorationists. However, Zeke eventually reported his parents to the Marley government. Along with the other Restorationists, they were captured, tortured, and sentenced to be turned into Pure Titans who would wander in Paradis Island. In return, Zeke would be raised by his grandparents.
After having witnessed his comrades and wife being turned into Titans and chase after their comrade, Grisha was saved at the last minute by Eren Kruger, the officer who had beaten him fifteen years earlier. The latter appeared to be the founder of the Restorationists and a holder of the Power of the Titans. He then proceeded to kill all the Marleyan soldiers and crush their boat. Once it was done, he set Grisha free, answered all his questions then charged him to continue the mission of their group. Grisha, at first reluctant, eventually accepted his mission and inherited Kruger's Titan power.
Later on, Grisha was found wandering outside Wall Maria near Shiganshina District by Keith Sadies, with no other memories besides his name and the fact that he was a doctor. Keith took him in and got him a job as a doctor in Shiganshina, where he also introduced him to Carla, who worked in the town as a waitress.
Sometime later, a plague hit Shiganshina and was cured by Grisha. After her parents and herself were cured, Carla thankfully embraced Grisha. Eventually, they got married and had a son, whom they named Eren.
In the year 844, Grisha and his son Eren went to the Ackermanns' house for a medical visit, and found that Mikasa's father and mother had been murdered, and their daughter Mikasa had been kidnapped. Grisha went to call the Military Police, and despite his warning to wait at the foot of the mountain, Eren alone tracked the kidnappers down, killed two of them, and freed Mikasa. After the third kidnapper appeared and began strangling Eren, Mikasa followed Eren's warnings and killed the criminal. Mikasa was then taken in by the Jaegers.
In year 845, after Eren and Carla have a discussion about Eren's wish to join the Scout Regiment, Grisha promises to show him an important secret he is hiding in the basement once he gets back. A still upset Eren flees from the house and Carla sends Mikasa after him.
While the three are away from home, the Colossal and Armored Titans breach the Wall of Shiganshina and a horde of Titans invades the district. One of the debris that flies out of the Wall due to the Colossal Titan's kick falls on the Jaegers' house, destroying it and crushing Carla's legs. Despite Eren and Mikasa's attempts to rescue her, Hannes drags them from there when a smiling Titan approaches. The kids then impotently witness as a helpless Carla is murdered and eaten by the Titan. After that night, Eren wakes up with no memory of his last moments with his father, but he still retained the key and after that day he always wore it around his neck. The two kids and their best friend Armin apparently live alone for the next two years and helped in the fields. In year 847 they enlist in the 104th Cadet Corps and three years later, the three graduate and join the Scout Regiment.
During his interrogation with Kitz Woermann, Eren recalls an interaction with his father on the night of the fall of Wall Maria. During this time, Grisha gives Eren the basement key and forces him take an injection that suppresses his memories. He tells Eren that he must let their memories guide him and get to the basement.
During the Battle of Shiganshina District, Eren crosses paths with Zeke, who recognizes and promises to save Eren after claiming they are both victims of Grisha. Eren, Mikasa, Levi, and Hange later go to the Jaeger family basement and find three books hidden in the false bottom of a drawer. The first contains a photograph of Grisha Jaeger with a woman and a little kid, revealing he came from beyond the Walls. The books tell Grisha's story, beginning with the day his sister Fay was killed off.
After the Marley Mid-East War, Zeke reunites with his grandparents who praise him for carrying out his mission successfully. During Eren's infiltration into Marley in the year 854, he meets with his half-brother Zeke in a hospital. Together, they discuss Eren's inheritance of their father's memories, and Grisha's slaughter of the Reiss family. Eren claims to disagree with his father's approach, stating that Eldians would not have to suffer if they had not been born. With this, Eren agrees to Zeke's euthanasia plan and takes a baseball as a token of their agreement.
Eren also meets his grandfather in the hospital whilst under the guise of being an amnesiac war-veteran named "Kruger". They have a conversation about the Grice family, and Mr. Jaeger asks Kruger to stop using Falco Grice for favors that could damage his family's reputation. He also tells Kruger to return to his family as soon as he is healthy. Eren notes Mr. Jaeger seems to have regrets surrounding his own family; he is solemnly told that the man regrets the fates his children met every day. Blaming himself because of the methods he used to raise his son, the elder Jaeger suffers a mental breakdown and is soon taken away.
A few days later at Willy Tybur's speech, Eren Jaeger has his name disgraced when he is declared to the world as the enemy of peace. In the resulting conflict, Eren inherits the War Hammer Titan, bringing a fourth Titan power into the possession of the Jaeger family.
In the year 844, Dr. Jaeger and his son, Eren, visit the Ackermann family for a checkup on the pregnant mother, with Eren quickly befriending their daughter, Mikasa. On Dr. Jaeger's subsequent visits, he informs Mikasa's father that his wife has an infection, which requires them to move closer to his house in Shiganshina.