Norwegian Monarch. He is also referred to as Sigurd Munn, or "The Mouth." He was the illegitimate son of King Harald IV Gille and one of his mistresses, Tora Guttormsdotter. His father was murdered in 1136 by Sigurd Slembe, a pretender to the Norwegian throne. Shortly afterward, he was declared king at Eyrathing and he co-ruled Norway with his half-brothers, Inge and Magnus Haraldsson, who were also declared kings in their respective regions. During their minority, Norway was ruled by their guardians, prominent among them was Inge's mother, Ingrid Ragnvaldsdotter. The guardians of all three infant kings joined forces against Sigurd Slembe and his ally, the former King Magnus IV Sigurdsson "The Blind", and defeated and killed them at the Battle of Holmengra near Hvaler (now part of Sweden) on November 12, 1139. Magnus Haraldsson died in the early 1140s and a fourth older half-brother, Eystein Haraldsson (Harald Gille had acknowledged Eystein as his son before his death), came from Scotland to Norway in 1142 and was given part of the kingdom. According to the Morkinskinna and Heimskringla sagas, the brothers ruled peacefully as long as their guardians were living. However, as the guardians died and the brothers became adults, conflict broke out between them. In 1155, a meeting was arranged between the brothers in Bergen that resulted in fighting between the men of King Inge and King Sigurd. According to some sources, King Inge accused his half-brothers of trying to overthrow him. King Sigurd denied the accusation; however, a few days later one of Sigurd's guards killed one of Inge's guards and Inge, on the recommendation of his mother and senior advisor, ordered his men to attack the house where Sigurd was staying. With only a few men, King Sigurd was unable to defend himself against King Inge's forces and on February 6, 1155 he was killed. At the time of his death, Norway had already begun a tumultuous period of internal civil wars which would last until 1240, that primarily involved a struggle between the Bagler and the Birkebeiner political parties over unclear Norwegian royal succession laws, social conditions, and conflict between the Church and the monarchy.