The First Fantasy Campaign mentions a nation known as the Northern Lords. David Ross identified these with the Eastern Skandaharians (Raiders to the East). Unlike their Western Cousins, the Raiders to the East have on occasions allied themselves with Thonia or Blackmoor against Western Skandaharians and have been counted among the forces of good. The Northern Lords have a less friendly relationship with Archlis though, and have been known to carry out raids against that city.
My impression from reading David Ross' work is that Thorsen is a Northern Lord who currently dominates both the Western and Eastern Skandaharians, though it is probably only a question of time before The Western Skandaharians rise against Thorsen. Thorsen's City, Borkshold is most likely located in the lands of the Raiders of the East.
David Ross also writes:
Borkshold has a mead hall with a big loot chest: 3000 gp and 4500 sp. The area has some kind of great shaggy russet-furred beast, probably from a bear but maybe a warg or even a mammoth. Only Thorsen has successfully brought one down (whatever it is).
Relationship with the Merrow:
Meremen are said to have a quarrel with the Skandaharians. It is unknown whether they distinguish between the Eastern and Western Raiders, but most likely they don't. I wonder what the Skandaharians may have done to offend the undersea races.