Britain

Britain is the home plane of the Knights of the Round Table, Merlin, Morgan Le Faye, the Holy Grail and Sir Mordred. Merlin was imprisoned in a crystal in that realm by Morgan Le Faye. Rather than a true "realm" as such, it is an island on Earth - and where Jagex is based. It is unknown if other islands or countries from Earth will be included in the game in future, but it is unlikely that any will. The Holy Grail is not a British relic, but King Arthur - in legend - is often associated with searching for it, although the player eventually finds it in the Fisher Realm.