In which country is most of Assassin's Creed Valhalla set?

Most of Assassin's Creed Valhalla is set in England.

The game follows Eivor, a Viking raider who leaves Norway and settles in England during the ninth century. Eivor's Raven Clan establishes a settlement and becomes involved in conflicts among the Anglo-Saxon kingdoms and Viking forces. England is therefore the main exploration area and the principal stage for the campaign.

Norway appears prominently at the beginning and remains available as a region, but it is not the game's main setting. The story also visits other locations, including Vinland and Asgard-inspired mythological realms presented through Eivor's experiences.

Valhalla's historical setting is during the Viking expansion into England, rather than the later medieval period often associated with castles and knights. The game uses fictionalized versions of historical rulers and places while combining them with the series' fictional Assassin-Templar conflict.