======High Kingdom of Manticore======
The basic premise of this setting is that the Rockall Bank was pushed up above sea level between 25 and 35 million years ago, forming a large and rather mountainous island to the northwest of the British Isles. This idea was originally mine (not that other people haven't thought of it before me), but the setting has since been influenced by a wide variety of ATLs, including the Tarrantry stories and the Tol Galen AU on Shipbucket.