The Ackerman family (アッカーマン家 Akkāman-ke?) is an Eldian family that lives within the Walls, but one of the few that are not Subjects of Ymir. Traditionally, they were a bloodline of warriors close to the crown, but were persecuted to the brink of extinction after refusing to follow the ideology of the First King. Only two known living members are left.
The Ackermans lived in Eldia prior to the raising of the Walls, and were "byproducts of Titan science". They were warriors close to the crown, and acted as the monarchy's right hand, entrusted with the survival of their people. After the Eldian Empire collapsed during the Great Titan War a century ago, members of this family moved inside the Walls that King Fritz created for the Eldians to live in.
When the King erased the memories of the people inside using the power of the Founding Titan, the Ackermans were immune to it due to not being Subjects of Ymir; the others included the Asian clan and those who would later become the noble families inside the Walls. However, along with the Asian clan, they rejected the King's idea of peace by being ruled by Titans, and turned their backs on the monarchy. Fearing his inability to control them, the King persecuted them, bringing both races to the brink of extinction.
At the end, the head of the Ackerman family offered his own life to ensure the survival of the bloodline and was executed. The rest of the generation avoided telling their children about the world before the Walls in order to protect them from the monarchy's purge. As a result, the following generations grew up without that knowledge.
Nevertheless, not even this stopped the oppression on them: Several generations later, the Ackermans were still being pursued and some of them sought refuge in the Underground City, while others fled to the mountains at the edge of the Wall. The purge only truly stopped after Uri Reiss, the King at the time, met Kenny Ackerman in an assassination attempt. The former apologized for the actions of prior monarchs on the latter's family, stopped the persecution, and accepted Kenny as his right-hand man.
The Ackermans have an "awakened power" displayed by some members of the family—a "byproduct of Titan science". Levi Ackerman describes it as "knowing exactly what needs to be done", and it lets the Ackermans exhibit physical abilities far above the average human. Due to this power, the Ackermans are often acknowledged as extremely powerful fighters: Levi is known as "humanity's strongest soldier"; Mikasa is regarded as the best soldier of her generation, "as valuable as a hundred average soldiers"; and Kenny was considered by Levi to be even more dangerous than himself, capable of killing more than 100 members of the Military Police without being caught.
This power is not automatically active, however, and has to be triggered by experiences in the Ackerman's life; it appears to be permanent afterwards. Mikasa was a normal girl until the age of 9, when three human traffickers killed her parents and kidnapped her. After witnessing one of the kidnappers strangling Eren and being urged by him to fight, Mikasa awakened her dormant power and was able to kill the criminal with a single stab; she was even able to snap the floorboards with the strength of her foot. Levi stated that he and Kenny also had similar moments that awakened their powers, although he did not lay out any specifics.
- The Ackermans were traditionally a bloodline of warriors who acted as the right-hand of the monarchs, and curiously enough, the three known "awakened" Ackermans ended up fiercely loyal to someone they know: Mikasa follows Eren Yeager everywhere; Levi trusts and obeys Erwin Smith; and Kenny was the bodyguard, right-hand man, and close friend of Uri Reiss, and continued to respect him years after his death.
- "Ackerman" roughly translates to "Ploughman". As "Acker" is a germanic word for "ploughed field."