In the distant past, a massive and powerful being known as a "Wyrm" arrived in this land inhabited by various insects. He molted into a smaller form to match the bugs and shared wisdom with those who had previously lived only by instinct.

These bugs, having grown into sentient beings, crowned the Wyrm as the 'Pale King,' marking the beginning of a highly advanced civilization: "Hallownest."

Hallownest flourished day by day. This civilization, stretching throughout the underground, built palaces and cities, shared a written language, developed a currency called Geo, and established transportation systems including Stagways, trams, and elevators.

The Pale King's fame soared, and after taking another Great Being, the White Lady, as his Queen, it seemed their happy life would continue forever.

The seeds of tragedy lay within the "Light." Before the Pale King—that is, the Wyrm—came to Hallownest, the bugs worshipped a mother deity of the Moth Tribe called "The Radiance." However, as even the Moth Tribe accepted the Pale King, the Radiance was gradually forgotten.

Unable to accept this, the Radiance lashed out, appearing in the bugs' dreams and infecting their bodies. This plague spread rapidly across all regions; infected bugs lost their self-awareness, attacked others, and even committed acts of self-harm.

In response, the Pale King quickly sealed off the cities and halted the operation of the Stagways and trams.

After much deliberation, the King decided to seal the Radiance, the source of the plague. However, to seal her, he needed to enter the dream world, which required a sacrificial vessel to host the dream. The King made a decision and began casting the eggs he sired with the White Lady into the "Abyss" beneath Hallownest.

The children who hatched there were burdened with the fate of being empty, pure vessels—lacking emotion, a heart, or even a voice to cry out in pain. From among countless vessels, the King chose the most suitable child and bestowed upon it the name "The Hollow Knight."

The Hollow Knight imprisoned the Radiance within its body, and even sturdier walls were erected to maintain the seal. Three Dreamers sacrificed themselves to uphold the seal: "Monomon the Teacher," "Lurien the Watcher," and "Herrah the Beast." Monomon and Lurien cooperated by the King's command, while Herrah cooperated through a deal to have the Pale King's child.

Currently, a wandering vessel known as "The Knight" has mastered the power of the Void, entered the dream, and slain the Radiance.