Castle Cousland has existed since the Divine Age, making it somewhere around 800 - 850 years old. Originally an outpost of the then-expanding Amaranthine Bannorn, it was ruled by the Elstan family, cousins of the Howe family. During the Towers Age (approximately 300 years later), however, Bann Conobar Elstan was allegedly murdered by his wife, Flemeth, which ended the bloodline. Conobar's captain of the guard, Sarim Cousland, acquired land and title, which the Cousland family has controlled ever since.
Eventually, the Couslands declared their independence from the Amaranthine, and instigated a war that lasted for thirty years. When the war finally ended, Highever was not only granted independence, but also half of what used to be southwestern Amaranthine.
During the Black Age, Highever became a teyrnir almost by default after the ruling Cousland (scholars disagree as to whether this was Mather or Haelia Cousland) battled, and defeated, the werewolf threat encroaching upon the land.
During the Unification of Ferelden, Teyrna Elethea Cousland fought King Calenhad in an attempt to maintain Highever's independence. When King Calenhad's army reached Highever, Teyrna Elethea led the local banns against him, but Calenhad won. After Elethea's men were defeated, Calenhad asked her to swear fealty. She did, thus allowing the Couslands to retain the teyrnir.
The former rulers of Highever are Teyrn Bryce Cousland and Teyrna Eleanor Cousland. Players who select the Human Noble origin will play as the second child of the Couslands, and the younger sibling of Fergus Cousland.
Arl Rendon Howe, during the early part of the game, will usurp the Teyrnir of Highever from the Couslands. Either the attack is implicitly mentioned if the Warden is not a Human Noble, or witnessed first-hand during the Warden's Origin if he or she is a Noble.After the Warden kills Howe and the Blight is finally thwarted, Highever is returned to the surviving Couslands (Fergus being the only survivor should the player not choose the human noble origin). As the eldest child of Bryce, Fergus is made Teyrn of Highever.
- Although present on the world map, it's impossible to go or return to Castle Cousland, Human Noble origin or not.
- If you talk to the Mad Hermit in the East Brecilian Forest and are a mage, human noble or dwarf, he will ask you where you came from. One of the choices is to say you came from Highever.
- During the Landsmeet's introduction scene, if you are a Human Noble, you can tell Loghain that you are Teyrn of Highever, after which you are rebuked by Arl Howe.
- Highever was home to several of the most famous figures in the Fereldan history. Human Noble Warden, Flemeth, and Calenhad Theirin were once living in this region.
- Duncan was also born here.