The war that swallowed Prythian — Hybern against the joined courts and the mortal realm, fought over the wall, the Cauldron, and the right to remake the world.
The War with Hybern
“And Nesta Archeron pointed. One finger—at the King of Hybern. A death-promise.”
ACOSF, loc. 132
The War with Hybern is the great conflict that breaks open Sarah J. Maas's second ACOTAR arc — the island kingdom of Hybern, ruled by its ancient King, moving to tear down the wall between the mortal and faerie lands and reclaim dominion over humanity using the stolen power of the Cauldron.
It is the war Feyre and the Night Court spend ACOMAF and ACOWAR trying to prevent, then survive: a story of broken treaties, courts forced into uneasy alliance, sisters dragged into immortality against their will, and a final battle on the human border where the cost of victory is measured in the dead.
At a glance
The conflict in brief
The cause
Why the war came
For five centuries an uneasy peace had held behind the wall — the magical barrier raised after the first great war to divide faerie Prythian from the mortal world. The King of Hybern, ruler of the island kingdom that never accepted that settlement, set out to tear the wall down, reopen the human lands to faerie conquest, and restore the age when mortals were chattel. To do it he sought the Cauldron, the primordial object of creation-magic from which all things were made, and the means to wield it.
The stakes
The Cauldron and the wall
The war turns on objects of immense power. The Cauldron is the source the King intends to weaponise — to unmake the wall and remake the world to Hybern's design. Around it gather the conflict's defining horrors and turning points, including the forced transformation of mortals into High Fae, an act that drags the Archeron sisters into immortality against their will and seeds consequences that ripple far beyond the war itself.
The alliance
Courts forced together
No single court could stand against Hybern. The war's spine is the struggle to forge an alliance out of Prythian's fractured, mutually suspicious courts — and to bring the mortal realm into a fight its people barely understand. The Night Court, with Feyre and Rhysand at its heart, works through ACOMAF and ACOWAR to assemble that coalition, racing Hybern's advance while the King's agents move to divide and pick off the courts one by one.
The reckoning
The final battle
The war ends in a pitched battle on the human side of the border, where the joined fae and mortal forces meet Hybern's army in the open. It is the costliest moment of the arc — alliances are tested to breaking, the dead are counted on both sides, and the King of Hybern is brought down at last. Among the war's most charged threads is Nesta Archeron's, who points one finger at the King and makes it a death-promise: of all those the Cauldron wronged, she is the one who marks him to die.
The legacy
What the war left behind
Victory does not come clean. The War with Hybern reshapes the map of Prythian, hardens and remakes the people who survive it, and leaves wounds — grief, trauma, and unfinished reckonings — that carry directly into the stories that follow. It is the hinge of the whole second arc: the catastrophe everyone tried to prevent, the crucible that forged the Night Court's family into what it becomes, and the war whose ash settles over everything after.
The war's key figures
Who fought it
From the page
Canon lines
“And Nesta Archeron pointed. One finger—at the King of Hybern. A death-promise.”
ACOSF, loc. 132