The Bitterbynde is a fantasy trilogy written by Australian writer Cecilia Dart-Thornton.
The King-Emperor is the Supreme Ruler of the Empire of (The Known Lands of) Erith, which dominates the world, Aia (or as some believe, the southern half.
In The Battle of Evernight, the protagonist, first called Tahquil and later by her real name, Ashalind, sets out to find the gate to a lost "Fair Realm" called Faerie, on the northern half of the world, Aia.
However, she is deterred and is taken prisoner by the main antagonist, a Faeren rebel and crown prince named Morragan.
The Bitterbynde Trilogy ends with Angaver and Ashalinnd going to be wed in Faerie, but being separated by the reincarnated Morragan and one of his followers, Nuckeluvee.