Reiss family

The Reiss family is an influential family living inside the Walls. While they masqueraded as a minor noble family living inside Wall Sina, they are in truth the true royal family who were in possession of the Coordinate until it was stealed by Grisha Yeager. Currently, Historia Reiss, the bastard daughter of the late Rod Reiss, is the ruling queen of humanity and the last living member.

History
Little is known about the Reiss family prior to the construction of the Walls. However, the First King, a Titan Shifter, constructed the Walls by use of the Coordinate. Even though he possessed the power to eliminate the Titans, he viewed a world ruled by the Titans as true peace. To accomplish this he controlled several Titans and forced them to harden their skin and encage themselves into the three Walls, Maria, Rose, and Sina. To protect the people, he erased their memories of the outside world and the history of the Titans.

Some time later, the First King gave the Coordinate to the Reiss family. The Reiss family ruled the Walls in secret by masquerading as a minor noble family. The King of the Walls would be their powerless figurehead. A special ritual would be conducted each generation. One Reiss would inject themselves with a serum and transform into a Titan and devour the previous holder of the Coordinate. This would give them the Coordinate, the lost memories of mankind, and Titan Shifting powers. However, this would also give them the ideology of the First King and make them decide to keep humanity under the Titans rule, even if they previously had a desire to free them. The Reiss who possessed the Coordinate would be the true king or queen of mankind at the time, as shown by Uri and Frieda. Usually, the ceremony would be conducted if the holder was too old or unhealthy.

One of the many holders of the Coordinate was Mr. Reiss, the father of Rod and Uri Reiss. Uri and Rod always begged him to exterminate the Titans, but he always refused. When it came time to pass his position to a son, Uri volunteered, asking Rod to pray. After the procedure, Uri had inherited the First King's ideology, but wished to build a paradise for mankind inside the walls. Since the Ackermans were being persecuted for being immune to the Coordinate's memory manipulation, he stopped the persecutions after a failed assassination attempt by Kenny Ackerman.

Many years later, Rod married and had five children with his wife; Ulkin, Frieda, Dirk, Florian, and Abel. He had also conceived a daughter with an attractive maid, Alma, his mistress and confidant. When it was discovered that Alma was pregnant, he sent her away to a ranch where she gave birth to Historia. Historia had an isolated upbringing and raised to believe she was an unfortunate mistake, which led to her martyr complex; she wished to die in a way in which everybody would remember her fondly and not hate her for existing. She had no friends and very little interactions with her family. She was friends with Frieda, who visited her in secret and taught her to read. Frieda told her to be a lady; a girl who was kind, gentle, and thought about those around her, a girl all would love. After her visits, she would wipe Historia's memory to protect her.

When Frieda was 15, she inherited the Coordinate by devouring Uri. Before she inherited the Coordinate, she was a cheery and generous girl who would be known to go to the fields to thank the farmers for their work. However, after becoming the true queen of humanity, she began to experience bouts of depression and mania. Historia mentions how she would go on ranting about how all humans were sinners and then feel very depressed afterwards. However, it was evident that she still loved her family.

Days after the fall of Wall Maria in 845, the Reiss family went to the Reiss Chapel to pray. However, Grisha Yeager, a Titan Shifter who lost his wife to the attack on Shiganshina, launched an attack on the Reiss family, attempting to exterminate the whole house. He fought Frieda as a Titan to the death, but Frieda was defeated due to not being able to control the Coordinate to its full potential and was eaten by Grisha. Grisha then killed the Reiss children and destroyed the Reiss Chapel, with the only survivors of the Reiss family being Rod, who fled blindly, and Historia, who wasn't present. Grisha then injected his son Eren with a Titan serum and allowed himself to be eaten, since Eren wasn't a Reiss, he wouldn't fall under the First King's ideology; and because of Eren's desire to slaughter the Titans, he could free humanity from their encagement.

Rod attempted to go to the farm and get Historia, possibly bringing her up as a true heir. However, the First Brigade of the Military Police beat them there, attempted to kill Historia and Alma, with Kenny Ackerman slitting Alma's throat. This was because they viewed Historia, an illegitimate child, as unfit. Rod decided on a way to keep Historia alive; she would give up her old identity, forsake any claims, and join the Survey Corps, hopefully dying by a Titan. This was seen as an acceptable alternative, and Historia was given the identity of Krista Lenz and sent to live in a refugee camp until she was old enough to enlist in the Military. Under her Krista persona, Historia was the lady Frieda wanted her to be, but also sought to die in a way that would be considered a martyr.

In the year 850, it is discovered that the Reiss family is the true royal family and Historia has a chance to claim the throne. However, Historia and Eren were captured by Rod and Kenny. Eren was bound and gagged underneath the Reiss Chapel in the same way all of the previous Coordinate holders were during the succession ritual. Rod continuously attempted to persuade Historia to transform and devour Eren. Historia was about to, until she learned that all the Reiss Coordinate users would fall under the First King's ideology. She refused to allow Rod to do this, so she smashed the Titan serum and attempted to free Eren and escape. Rod was shocked and crawled on the floor and licked the evaporating Titan serum, deciding to devour Eren himself. This, however, transformed him into a 120 meter Deviant Type Titan and destroyed the Reiss Chapel. With Rod being a mindless Titan, he began to move towards Orvud District. The Garrison and Survey Corps led an attack on him, using explosives to blow his hands and head off. They then attempted to cut the nape of his neck, with Historia delivering the final blow.

After this, Historia took the throne as queen. Historia, however, let the Scouts do much of the ruling for her, preferring to run an orphanage ranch in Wall Sina. The orphanage is composed of all of the children orphaned in the Walls by the Titans and in the Underground Districts. She does, however, sanction the operation to reclaim Wall Maria.