Over 1,800 years ago on an alternate world, the human, Ymir Fritz, made a contract with the "Devil of All Earth" and became the first giant humanoid creature called a Titan (巨人, Kyojin). When Ymir died 13 years later as a side effect of having the Titan ability, her spirit split into nine Titans; the Founding Titan, the Attack Titan, the Colossal Titan, the Armored Titan, the Female Titan, the Beast Titan, the Jaw Titan, the Cart Titan, and the War Hammer Titan. They formed the Eldian Empire, the Founding Titan remaining with the Fritz family, defeating the Marley nation and ruled over it for 1,700 years. However, 100 years ago, Eldia's 145th King Karl Fritz, corrupted and power-hungry, arranged for his country's fall by Marley and retreated to the island of Paradis. There, he used countless Colossal Titan bodies to construct the walls. He erased the memories of most of the people he brought with him with his Titan power so they knew nothing about the outside world. Because memories of those with Titan powers are passed to the next Titan, his descendants were influenced into continuing his work of ruling the Eldians within the walls through promoting fear of a Titan attack. Meanwhile, the Eldians who remained in Marley suffer as second-class citizens with some being exiled to Paradis and turned into Titans which then terrorize the island's residents.