Medieval Sweden

Swedish pre-history ends around 800 CE, when the Viking Age begins and written sources are available. The Viking Age lasted until the mid-11th century, when the Christianization of Scandinavia was 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 led the unification of Sweden, was crowned — is considered the Younger Middle Ages.

During this period, Sweden was gradually consolidated as a single nation. Scandinavia was formally Christianized by AD 1100. The Kalmar Union between the Scandinavian countries was established in 1397 and lasted until Gustav Vasa ended it upon seizing power.

Until the 9th century, the Scandinavian people lived in small Germanic kingdoms and chiefdoms known as petty kingdoms. These petty kingdoms and their royal rulers are mainly known from legends and scattered continental sources. The Scandinavian people appeared as a group separate from other Germanic nations, and at this time there was a noticeable increase in war expeditions (Viking raids) on foreign countries, which has given the name Viking Age to this period. At this time the seas were easier to travel than Europe's inland forests, and the wild buffer regions that separated the kingdoms of the time were known as marches.

While the Danes and Norwegians went west and southwest in Europe, Swedes had their political interest mainly directed towards east and southeast in Europe. The large Russian mainland and its many navigable rivers offered good prospects for merchandise and, at times, plundering. These routes brought them into contact with the Byzantine and Muslim empires. Since the East was rich and well-defended, Viking activity there centered mainly around peaceful trade instead of the pillaging typical in Western Europe.

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