Ymir Fritz was the first person to obtain the power of the Titans. She was a slave of the Eldian king, who abused her power to bring prosperity to Eldia while devastating Marley and the rest of the world. Thirteen years after awakening her power, she died protecting the king; her corpse was then forcibly cannibalized by their daughters, Maria, Rose, and Sheena. Her powers then split into what eventually came to be known as the Nine Titans.
Upon her death, Ymir was transported to the Coordinate, where she molded Titans out of the sands and obeyed the royal family whenever they sought the Founder's power.