Arlert family

An Eldian household from Shiganshina District, the Arlerts hold no power or land, yet curiosity defines them. Possessing knowledge of the outside world is forbidden inside the Walls, and the family keeps it anyway, at terrible cost.

Before Wall Maria falls, Armin's parents secretly construct a hot air balloon. The Military Police uncover the project and kill the couple as they attempt to escape with their craft. Armin's grandfather preserves a different inheritance, an illegal volume describing burning lakes and snowfields of sand, which he eventually passes to his grandson. At nine years old Armin shows the book to Eren Yeager, planting the fascination with the outside world that drives the entire story.

The Colossus Titan's attack on Shiganshina in 845 sends Armin and his grandfather fleeing behind Wall Rose; during the escape, Armin's warning to the soldier Hannes saves Eren and Mikasa from being devoured. A year later the government disguises a culling of refugees as an operation to reclaim Wall Maria, and the old man dies in it. Armin spends the following year farming alongside Eren and Mikasa before enlisting in the 104th Training Corps in 847.

Armin Arlert, the family's only living member, compensates for weak physical scores with an exceptional mind. He devises the plan that seals the Trost breach using Eren's Titan, unmasks Annie Leonhart as the Female Titan, and serves under Captain Levi in the Special Operations Squad, briefly commanding it during the push to retake Shiganshina. Erwin Smith counts him among the military's greatest weapons. Left at death's door when that battle ends, Armin receives the Titan injection, devours Bertolt Hoover, and brings the Colossus Titan's power into the Arlert line. His father, mother, and grandfather make up the family's three deceased members.