Bagler The Bagli Party or Bagler ( Old Norse : " Baglar " ; Norwegian : " Bagler " ) was a faction or party during the Norwegian Civil Wars . The Bagler faction was made up principally of the Norwegian aristocracy , clergy and merchants . It was formed in Skåne , then part of Denmark , in 1196 principally by Bishop Nicholas Arnesson of Oslo and Archbishop Erik Ivarsson of Nidaros around the pretender Inge Magnusson ( nicknamed the Baglar - King ) to depose King Sverre Sigurdsson . It contested with the Birkebeiner s , essentially a faction of peasants , led by the pretender King Sverre , for control in a Norwegian civil war during the late 12th century . Sverris saga provided Sverre a royal lineage as putative bastard son of the late king Sigurd II of Norway , which in the Norway of the time provided him a claim to the throne . Historians generally agree with the consensus of his time that he was a pretender / impostor . The civil wars period of Norwegian history lasted from 1130 to 1217 . During this period there were several interlocked conflicts of varying scale and intensity . The background for these conflicts were the unclear Norwegian succession laws , social conditions and the struggle between church and king . There were then two main parties , firstly known by varying names or no names at all , but finally condensed into parties of Bagler and Birkebeiner . The rallying point regularly was a royal son , who was set up as the head figure of the party in question , to oppose the rule of the king from the contesting party . From a socio - historical perspective , Bagler can be interpreted as conservatives against the results of developments such as the rapid increase in landless border men ( " markamenn " ) , who settled along the Swedish border and made their living by pillaging the rich old settlements . That lawless population became the foremost basis of the Birkebeiner . Bagler also favoured the church and its privileges and possessions . Viken and Vestlandet , where social distinctions were growing deeper , were gaining more power at the expense of Trøndelag , a region where the social tensions were not as marked . The wealthier classes , particularly in Viken , were the basis of the Bagler party . The powerful old Trønder families were simply being left behind by their peers in the south , who had acquired a strong leader in the Vestland earl Erling Skakke in the mid - 12th century . The antecedents of the Bagli party had been supporting the rule of King Inge I of Norway and after him , King Magnus V of Norway ( killed 1184 ) and the latter ' s father and regent , earl Erling Skakke ( killed 1179 ) . The Birkebein faction had been formed in 1174 to depose Magnus and Erling . The Birkebeiner continued earl Erling ' s centralization which underscores the geographical motivations behind the conflicting parties . The Birkebein policy during Sverre did not seek a social revolution , only to move the centre of power back to Trøndelag . Around the year 1200 , these rival groups shared the identical but opposite goal of controlling the entire country . King Sverre managed to acquire control of much of Norway , but in Hedmark and Østerdal , the Baglers remained powerful . Upon Sverre ' s death in 1202 , the Bagler power increased . Sverre ' s successor , King Haakon III of Norway , died after a two - year reign in 1204 , leaving his posthumous son Haakon Haakonsson in Hamar , which was under Bagler control . In 1206 , a group of the Birkebeiners set off on a dangerous voyage through treacherous mountains and forests , taking the now two - year - old Haakon Haakonsson to safety in Trondheim . Norwegian history credits the Birkebeiners ' bravery with preserving the life of the boy who later became King Haakon IV of Norway . The Birkebeins managed to hold some power , despite short reigns of their monarchs after Sverre . In 1209 , a pact was made between Bagler and Birkebeiner , which recognized Bagler pretender Philip Simonsson as ruler of Oppland and Viken in Eastern Norway , without the title of king , and recognized Birkebeiner ' s Inge Bårdsson as King Inge II of Norway . They both died in 1217 and Birkebeiner - born Haakon IV ascended the throne , relatively unopposed , under the regency of Duke Skule Baardsson . Later in 1240 , Haakon IV ended the civil wars and weakened the role of the aristocracy in Norway .