Leidang

The institution known as leiðangr (Old Norse), leidang (Norwegian), leding (Danish), ledung (Swedish), expeditio (Latin) or sometimes lething (English), was a form of conscription (mass levy) to organize coastal fleets for seasonal excursions and in defense of the realm typical for medieval Scandinavians and, later, a public levy of free farmers. In Anglo-Saxon England, a different system was used to achieve similar ends, and was known as the fyrd.

The first recorded instance of a Norse lething is disputed among scholars. There is considerable evidence that substantiates its existence in the late 12th century. However, there are also written sources and archeological evidence which indicate that the lething system was introduced as early as the tenth century, if not earlier.