What Happened to the 2 Lost Legions of Warhammer 40K the Emperor Allegedly Ordered to be Executed

The mystery of the two lost Space Marine Legions—the II and XI—remains one of the greatest enigmas in Warhammer 40K lore. The Emperor of Mankind created 20 Primarchs, each leading their own legion. However, the II and XI Legions have been completely erased from the Imperial record.

Known as the “Forgotten and the Purged,” their erasure from all records is one of the most severe punishments ever imposed by the Imperium. Fans have had theories, but the truth behind their fate remains a mystery. Were these legions traitors, victims of fate, or something even more sinister? We may never know the full truth.

What Do We Know About The Lost Primarchs of Warhammer 40K?

The Lost Legions have been expunged from Imperial records through a process known as the Damnatio Memoriae—a condemnation of memory. This is an edict reserved for the most disgraced figures and it systematically wipes out any mention of the legions and their Primarchs.

Fun 40k lore fact: Despite common conceptions, we know what happened to one of the Lost Primarchs. Here’s the excerpt from the Horus Heresy Black Book Thirteen: Apocalypse.#warhammer40k #WarhammerCommunity #warhammer40000 #HorusHeresy pic.twitter.com/7h3eMeGD0x

— Marshal Bohemond ⚔️⛨ Space Crusader Vtuber (@HMBohemond) April 1, 2023

What makes this punishment more significant is that even the traitor legions, who openly rebelled during the Horus Heresy, retained some records in Imperial history. The total disappearance of the IInd and XIth legions indicates their offense was seen as far worse. Maybe we’ll see these events in the future, Games Workshop does add more lore all the time.

What is known about these two Legions is scarce, as Imperial records were meticulously destroyed. The only remaining clues are their empty plinths in the Investiary of the Imperial Palace on Terra, where statues of the 20 Primarchs once stood.

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These statues represented the Emperor’s genetically engineered sons who led the Legions during the Great Crusade. By the time of the Horus Heresy, however, the plinths of the II and XI Legions had been vacant for an unknown period, hinting at some tragic event that led to their erasure.

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The Horus Heresy novels and codices provide no definitive answers, leaving much to the imagination of players and fans. For many, the mystery of the Lost Legions adds a layer of intrigue and depth to the already expansive Warhammer 40K universe.

There Might Just Be No Deeper Reason Than Just Mystery

Rick Priestley, one of the original creators of Warhammer 40K, mentioned in an interview that the erasure of the two Legions might have been tied to their redemption. According to him, while they may have committed heinous acts, they were forgiven and forgotten, their crimes erased along with their names. A bit similar to Titus in Space Marine 2. Though, Titus didn’t disappear.

My extended interview with Rick Priestley
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This contrasts sharply with the fate of the traitor Legions, whose betrayal remains a part of recorded Imperial history. The idea that the Lost Legions were redeemed, only to be erased, makes their fate all the more tragic and mysterious.

Some fan theories speculate that the two Legions may have participated in the infamous Rangdan Xenocides, one of the deadliest campaigns of the Great Crusade. However, this involvement remains largely undocumented, and it’s unclear whether their actions in the campaign played a role in their eventual downfall.

However, Priestley also emphasized that the decision to leave these Legions shrouded in mystery was intentional. He envisioned them as part of a mythic past, something “unknowable,” rather than a storyline with a definitive answer.

What do you think of the Lost Primarchs of Warhammer 40K? Let us know in the comments!