[1] It directly influenced Henrik Ibsen's The Pretenders, written the following year, which explores some similar themes.
[2] The trilogy is based on the history of the real Sigurd Slembe, a 12th-century pretender to the Norwegian throne, whose story was told in the medieval kings' sagas Heimskringla, Fagrskinna, and Morkinskinna.
Sigurd's mother Tora confesses that he is the illegitimate son of her sister's husband, King Magnus Barefoot.
It is now 1136 and Sigurd has returned to Stavanger to seek the recognition of King Harald Gille, his half-brother who had acceded to the throne six years earlier.
Shortly before going to his defeat and death at the Battle of Holmengrå in 1139, Sigurd bids farewell one last time to his mother, who is now a penitent nun, and asks to hear "the Crusader's Song" so that he "may joyfully go hence after that".