The Norwegian nobility (the lendmenn) have cooperated during the minority of the brothers, Sigurd, Inge and Magnus, sons of Harald Gille, king of Norway, to rule the kingdom and advise the kings.

Their half-brother Eystein had in 1142 come to Norway from Scotland.

His parentage had been accepted, since Harald Gille had acknowledged that he had a son overseas.

Eystein had thus become king and co-ruler together with Sigurd and Inge.

Magnus, of whom little more is known, had at some point in the 1140s died of natural causes.

As they grew up, and their old advisors died, hostility had begun to grow among the three surviving half-brothers.

All three of them are set to meet in Bergen in 1155 in an effort to keep the peace.

Inge accuses Sigurd and Eystein of planning to have him dethroned.

Sigurd denies the accusations, but a few days later one of Inge's guards is killed by one of Sigurd's.

At the advice of his mother Ingrid and his senior advisor, Gregorius Dagsson, Inge orders his men to assault the house where Sigurd is residing.

The King has but few men, and no mercy is given, and on February 6, 1155, Sigurd falls.

He is buried by the old cathedral of Bergen, in what is today Bergenhus Fortress.

(This cathedral will be demolished and replaced by a larger cathedral soon after.)

King Eystein is late in arriving for the meeting, and only approaches the city after Sigurd is already dead.

An uneasy settlement is reached between Inge and Eystein, but peace between them will not last long.

As it turns out, the killing of king Sigurd has started the second phase of the Norwegian civil war era, with fighting continuing until 1208 with only short breaks.