why did eren start the rumbling

Eren started the Rumbling because he became convinced that destroying most of humanity was the only way to secure freedom and safety for the people of Paradis, but the story also shows that his motives are tangled up with fatalism, trauma, and a selfish desire to act on his own violent impulses. Different episodes, manga chapters, and even creator and critic commentary present overlapping but not perfectly consistent reasons, which is why this question is still a major debate in forums and essays.

Core in‑story reasons

From inside the story, several key factors push Eren to trigger the Rumbling.

• He believes the outside world will never accept Eldians from Paradis and will eventually exterminate them, so annihilating external threats first is, to him, “self‑defense” on a genocidal scale.

• Diplomatic attempts and contact with Marley convince him that most of the world sees Eldians only as devils, not as people worth negotiating with.

• After seeing future memories when he touches Historia’s hand, he concludes that the path where he starts the Rumbling is already “set,” and he resigns himself to walking that path.

In his own speeches as the Founding Titan, he frames the Rumbling as the only way to ensure freedom for his friends and his island, even if it means becoming the enemy of all humanity.

Trauma, rage, and ideology

Eren’s deeper psychology makes the Rumbling feel almost inevitable given who he is.

• He grows up hating Titans, then learns that Titans and the people he wants to protect are part of the same Eldian system, which twists his hatred into something larger and more abstract.

• The loss of his mother, years of war, and constant betrayal harden his black‑and‑white worldview: either his people die, or the rest of the world does.

• Commentators often point out that Eren is obsessed with the idea of absolute freedom, defined as acting without restraint, and the Rumbling is the ultimate expression of that destructive freedom.

Several analyses argue that his ideology evolves from “kill the Titans” to “tear down the entire world that created Titans and persecution,” which is why a partial, limited Rumbling never satisfies him.

Future memories and fatalism

The time‑loop style memory mechanics of the Attack Titan power are crucial to why he starts the Rumbling.

• Eren sees memories of the future—including the Rumbling—when he kisses Historia’s hand, which makes him feel that the massacre is inevitable.

• His influence on his father through Attack Titan memories shows that his future self pushed events toward this path, reinforcing the idea that he is both victim and author of his own destiny.

• This time paradox makes him feel “trapped” in a script where his only role is to become a monster so his friends can one day stop him.

Many readers interpret this as commentary on predestination: Eren “chooses” the Rumbling, but he also believes he had no real alternative.

“I did it for me” and the final twist

Late‑series dialogue and post‑finale commentary complicate the idea that he was purely sacrificing himself for others.

• In the finale conversation with Armin (as reported and discussed in analyses), Eren admits that part of him simply wanted to destroy the world and keep moving forward, exposing a selfish core under his justification.

• Some critics compare him to Walter White: someone who says they did everything for loved ones but ultimately pursued their own desire to feel powerful and free.

• He also explicitly intends to turn himself into a unifying final enemy, so the rest of humanity can band together, defeat him, and then see his friends as heroes instead of devils.

This makes the Rumbling both an act of martyrdom and a colossal, ego‑driven tantrum: he creates an apocalypse and then hands the world a chance to rebuild on his corpse.

How fans and critics interpret it

Discussions on forums and in essays keep circling back to a few main interpretations.

• Political/strategic reading: Eren is a cold realist who correctly sees that the world will never accept Eldians, so the Rumbling is a horrific but “rational” survival strategy.

• Psychological reading: the Rumbling is the endpoint of an abused, traumatized child who never learned to process loss, and who uses power to lash out at an entire world.

• Meta/textual reading: Eren embodies the dark extreme of shonen “move forward no matter what,” showing what happens when that mindset is taken literally to genocide.

Most nuanced takes combine these: he is a frightened kid, a ruthless strategist, and a selfish destroyer all at once, and the Rumbling is the horrifying intersection of those selves.

TL;DR: Eren starts the Rumbling because he believes it is the only way to guarantee Eldian survival and his friends’ future, but time‑looped memories, a fanatical obsession with freedom, deep trauma, and his own selfish desire to destroy all play directly into that choice.

Information gathered from public forums or data available on the internet and portrayed here.