Kingdom Under Fire: Circle Of Doom is the fourth installment in the Kingdom Under Fire series and the first released for the seventh generation of consoles. Chronologically the game's story follows Kingdom Under Fire: The Crusaders released in 2004. Unlike the previous Kingdom Under Fire games in the series, Circle of Doom's lacks the real-time strategy elements, with much of the gameplay focus being on hack and slash combat.

The story begins when Nibel The Lord of Light made a pact with Encablossa Lord of Darkness, the pact being that each lord will rule his age and the other will wait until the other finishes his rule. But eons pass and Nibel grows weary of seeing his creatures becoming monsters and being tortured so when the Age of Light was about to end Nibel didn't give his rule to Encablossa. Encablossa was angry so he gathered his Dark Legion and attacked the world, many ages pass but in Crusaders, Walter's soldiers destroyed the ancient heart (a powerful relic and the center of the conflict in 'Kingdom Under Fire') and Encablossa appeared in the form of a great demon, but he is defeated By Kendal and Regnier's forces but the heroes then become trapped in Encablossa's Dimension as old heroes. In Regnier's campaign it is explained that the dark dimension is about to explode with the resulting blast poised to consume both dimensions.