Bagler is a term that refers to a faction in medieval Norway during the 13th century. This group emerged as a rival to the Birkebeiner faction, which supported King Håkon Håkonsson. The Baglers were primarily composed of nobles and their supporters who opposed the king's rule and sought to establish their own power. The conflict between the Baglers and the Birkebeiner led to a series of civil wars known as the Norwegian Civil Wars. These struggles significantly impacted Norway's political landscape, contributing to the eventual unification of the country under a single monarchy.