leiðangr

The leiðangr was a system of naval conscription and militia service used in medieval Norway. It was a mandatory levy of ships and men that could be called upon for military expeditions, primarily for defense and raiding. The system was organized geographically, with districts responsible for providing a certain number of ships and their crews. Each ship was typically a longship, and the crew size varied depending on the vessel's dimensions.

The leiðangr was not a standing army but rather a mobilization system. When a call was issued, the required ships and men would assemble. The purpose of the leiðangr could range from repelling invasions to offensive raids on foreign shores, as well as supporting royal authority within Norway. The organization of the leiðangr evolved over time, with royal decrees and laws detailing its structure and obligations. Exemptions or alternative payments might be possible in some circumstances. The system was a significant aspect of Norwegian society and military organization during the Viking Age and into the medieval period, playing a crucial role in the kingdom's defense and expansionist ambitions.