Yeager family

The Yēgā-ke (イェーガー家) is the family where the protagonist of Attack on Titan, Eren Yeager, hails from. They also legally adopted Mikasa Ackerman in the year 844. They were originally stationed at Shiganshina District on the southern edge of Wall Maria, but originated from an advanced society living outside the Walls.

History
The Yeager family was the descendants of Eldians who stayed in Marley after the Great Titan War. They lived in the Liberio Internment Zone, where people like them were forced to live by the government.

One day, Grisha and his little sister Fay left the ghetto without permission in order to follow a blimp flying in the sky. They crossed a town before eventually reach their goal. As they watched the blimp landing, two Marley soldiers noticed them and asked them if they have a permit exit to leave the Liberio Internment Zone. Grisha admited 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 here. The two soldiers Grisha met earlier came and explained to the parents they found their daughter's body but did not know the cause of her death. In addition, they scold them for their children's behavior and adviced them to teach Grisha the deeds of their ancestors, which Mr. Yeager did.

Years later, Grisha followed his father's footsteps and became a doctor. He joined the Eldia 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. They got married and had a son they named Zeke.

A few years later, the Marley government announced they were at war with Paradis and were looking for Eldians children to become part of the army and host the power of the great 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 Eldia 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 mindless Titans who would wander in Paradis.

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 soldier who had beaten him fifteen years earlier. The latter appeared to be the chief of the Eldia Restorationists and a Titan shifter. He then proceed to kill all the Marleyan soldiers and crush their boat. Once it was done, he set Grisha free, answered to all his questions then charged him to continue the mission of their group. Grisha, at first reluctant, eventually accepted his duty and gained Kruger's powers.

Later on, Grisha was found wandering outside Wall Maria near Shiganshina District by Keith Shadis, with no other memories besides his name and the fact that he was a doctor. Shadis 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.

Some time 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 year 844, Grisha and Eren went to the Ackermans' house for a medical visit, and found that Mr. and Mrs. Ackerman had been murdered, and her daughter Mikasa had been kidnapped. Grisha went to call the police, and despite his warning to wait downstairs, Eren alone tracked the kidnappers down, killed two of them, and freed Mikasa. After the third kidnapper appeared and began strangling Eren, Mikasa awakened her dormant Ackerman power at Eren's urges and killed the criminal. Mikasa was then adopted by the Yeagers.

Fall of Shiganshina arc
In year 845, after Eren and Carla have a discussion about Eren's wish to join the Survey Corps, Grisha promises him to show him an important secret he is hiding in the basement, and then leaves to work. A still upset Eren flees from the house and Carla sends Mikasa after him. But while the three are away from home, the Colossus and Armored Titans breach the Wall on Shiganshina and a flood of Titans invades the district. One of the debris that flies out of the Wall due to the Colossus Titan's kick falls on the Yeagers' house, destroying it and crushing Carla's legs. Despite Eren and Mikasa's attempts to rescue her, Hannes drags them from there when the Smiling Titan approaches. The kids then impotently witness as a helpless Carla is murdered and eaten by the Titan. Later on that night, Grisha hears the news of the fall of Shiganshina and, enraged at the Reiss family due to their refusal to free humanity from the Titans despite possessing the power to do it, goes to the Reiss Chapel and faces the then holder of the Coordinate, Frieda Reiss. The two of them transform into Titans and fight, but Grisha defeats Frieda and eats her, murdering her and stealing the Coordinate. He then proceeds to slaughter the whole family, with the exception of Rod, who barely manages to escape, and Historia, who was living in a farm by then.

Grisha then goes to the shelter where Eren and Mikasa are staying as refugees and learns from Eren that Carla has died. Grisha takes Eren into the forest and, as he gives him the key to the basement and instructs him to find it by all means, he injects Eren with a Titan serum, triggering a transformation into a Titan by Eren. The now mindless Titan Eren grabs Grisha and bites him in half, inheriting his Titan shifting and Coordinate powers. After regaining his human form, Eren finds the remains of his father next to him and passes out in shock. He is later found by Keith Shadis, who takes him back to the shelter.

Eren later wakes up with no memory of that event as a side effect of the Titan serum, 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 Arlert apparently live alone for the next two years and helped in the fields. In year 847 they enlist in the 104th Training Corps and three years later, the three graduate and join the Survey Corps.

Return to Shiganshina arc
Eren, Mikasa, Levi and Hange go to the Yeager basement and find three books hidden in the false bottom of a drawer. The first contain a photograph of Grisha Yeager 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.