The historical setting of Assassin's Creed Valhalla begins in 873. The game follows Eivor, a Viking who leaves Norway with a clan and establishes a settlement in England during the Viking expansion.
Valhalla's main historical campaign takes place during the late ninth century, when several Anglo-Saxon kingdoms are competing for power. Eivor's story intersects with figures such as Alfred the Great and with the Hidden Ones, the predecessors of the Assassin Brotherhood.
The year 793 is famous for the Viking raid on Lindisfarne, but it is not Valhalla's opening year. The game begins decades later, and 878 is another important date connected to the broader Viking Age and Alfred's campaigns. These nearby dates can make the chronology easy to mix up.