Although it officially has no occupant in order to maintain peace and equality between nations, it is actually occupied by the enigmatic Im, whose authority supersedes the Five Elders.
The Empty Throne is an extremely tall, ornamented red and gold throne that bears the symbol of the World Government. The golden armrests are designed to look like lion head statues.
The throne itself is kept on top of a three-level red and white platform, and has several swords and axes planted in the floor of the first and third levels, with the ones in the first being rusting relics of the twenty founding kingdoms.
According to an employee of the World Government, the Empty Throne has existed since the Void Century, 800 years before the story's present time. Each of the twenty weapons placed around the throne are supposed to represent one of the twenty kingdoms that founded the World Government, symbolizing their protection over the seat.
The false premise is that no one is allowed to sit on this throne, not even the Five Elders or the World Nobles, as its vacancy symbolizes that the world is not ruled by a single figure, sending a message of peace by making all royals equal before it with none greater or lesser than the other. The kings and queens attending the Levely are required to pledge that they won't take the throne for themselves in greed, just like the original twenty founding kings once did.
In truth, the Empty Throne is secretly occupied by the mysterious Im, a person with authority over the Five Elders.
Sterry, being a power-hungry and spoiled king, openly expressed his desire to sit on the Empty Throne while being instructed to take the pledge not to, symbolizing his latent wish to be the singular ruler of the entire world.