He is a good example of how even in countries without strong feudal inheritance policies vassal-ship could be passed down from father to son.
In 1247, he was one of the nine liegemen (Gaut Johnsson, Lodin Gunnisson, Gunnar Kings Kinsman, Munan Byskopson, Finn Gautsson, John Queen (Liegeman), and Sigurd Byskopson) listed at a re-coronation feast which the king held to establish his legitimacy.
[2] Later, he also participated in the 1263 attack on Scotland and is listed as one of the important men in King Haakons specially picked crew.
[4] He is listed first among the four liegemen who were at King Haakon's side at his deathbed (Brynjolf, Erling Alfson, John Queen (Liegeman), Rognvald Ork).
This appears to be the last mention of Brynjolf and it is likely he retired from public life and died a few years later.