Karl Fritz

"So the First King would call this true peace? What a funny way to look at things."

- Hange Zoë on the First King

The Shodai-ō (初代王), also known as King Reiss (レイス王) and King Fritz (フリッツ王) and known during the Great Titan War as the 145th King of the Fritz family, was the Titan Shifter who created the walls and modified the memories of the humans inside, erasing all the history of the world before that event, as he believed a humanity ruled by Titans to be true peace.

Appearance
The First King's human form is unknown, but in Titan form he seemed to be of a very tall class. He had long, straight hair and sharp teeth. In contrast to his thick legs, the upper part of his body was quite skeletal, with his ribs visible through his skin. His arms were thin and long, similar to those of the Beast Titan.

History
Over a century before the battle of Trost, the 145th King of the Fritz family inherited the power of the Progenitor Titan. For many hundreds of years, eight houses led by the eight Titan Shifters subservient to the Fritz family were constantly at war with each other. Rather than following the method of his ancestors and using the Progenitor Titan to maintain order in the nation of Eldia, King Fritz chose instead to move the capital of Eldia to the island of Paradis to the east of the mainland of their nation. In the King's absence, the oppressed society of Marley instigated the Great Titan War in Eldia, taking control of seven out of the nine Eldian Titans and rising up against their oppressors.

Rather than leaving Paradis and contributing to the war, King Fritz chose instead to gather the royal family and the people of Eldia to the island. When humanity had gathered to Paradis, King Fritz used the power of the Progenitor Titan to construct guide tens of millions of Colossus Titans in the construction of the three concentric Walls Maria, Rose, and Sheena around the last remaining territory of Eldia in which the subjects of Ymir could finally live in true peace.

After the Eldians were inside, he used his power again to alter their memories, erasing all knowledge about the world outside the Walls and the history before that event. The only bloodlines unaffected by this manipulation were the minority bloodlines within the walls, such as the nobles, the Ackerman family, and the Asian clan.

King Fritz, now the First King of the newly named Reiss family, later gave the Progenitor Titan to a descendant in the Reiss family, presumably dying in the process as it was likely passed on in the same succession ritual that Uri Reiss and Frieda Reiss participated in.

Legacy
The Reiss family continued passing down the Progenitor Titan between them from generation to generation long after the First King's death. This was done by having the successor transform into a Titan and devour the previous user; thus gaining the Progenitor Titan, Titan Shifting abilities, the lost memories of mankind, and even the ideology of the First King; keeping them from sharing their knowledge and from ever freeing humanity from their encagement.

Abilities
The First King was a Titan Shifter and the original holder of the power of the Coordinate, or Progenitor Titan, and displayed many abilities related to that power; some of them at a rather advanced level. His powers included:


 * Memory Manipulation: He used this power to erase all mankind's memories before the building of the Walls. However, for some reason, that power did not affect the members of the Ackermans, the Asian bloodline, and the noble families.
 * "Titan Control": The First King used this power to control Titans and build the Walls, by making them harden their bodies and confine themselves into the resulting structures.
 * "Memory Inheriting": He was able to pass down his memories to an unknown member of the Reiss family after dying, making them the holder of the lost memories of mankind. This also happened with all of the other inheritors, who inherited the memories of the First King and the inheritors themselves. However, they and all their subsequent heirs also inherited his belief that a world ruled by Titans would be "true peace". This influence is so strong that even people that wanted to stop the Titans changed their minds when they received the power, deciding not to make a move and refusing to reveal the reason, even to their own families.
 * "Titan Shifting": Little is known about his abilities as a Titan Shifter, except for the fact that he had enough control to retain his intelligence while transformed; since he was seen surrounded by a crowd of people without attacking them, and without any of those people trying to flee.

Trivia

 * Hange Zoë created the term "Progenitor Titan" (始祖の巨人) to refer to the Coordinate and any Titan Shifter who could master its power, including the First King.