What is "ranrike"

Ranrike or Rånrike ( Old Norse Ránríki) was the old name for a part of Viken, corresponding to southeast Norway (Oslofjord area) and the northern half of the modern Swedish (Norwegian until 1658) province of Bohuslän (roughly identical with Álfheimr of Scandinavian mythology). When folklore and culture is concerned the usage has been revived to refer to northern Bohuslän.