Swedish pre-history ends around 800 CE, when the Viking Age begins and written sources are available.

The Viking Age lasts until the mid-11th century, when the Christianization of Scandinavia is largely completed.

The period 1050 to 1350 — when the Black Death struck Europe — is considered the Older Middle Ages.

The period 1350 to 1523 — when king Gustav Vasa, who leads the unification of Sweden, is crowned — is considered the Younger Middle Ages.

During this period, Sweden is gradually consolidated as a single nation.

Scandinavia is formally Christianized by 1100.

The Kalmar Union between the Scandinavian countries is established in 1389 and lasts until Gustav Vasa ends it upon seizing power.