Hannes Hafstein by sculptor Einar Jonsson, Reykjavik, Iceland
Hannes Hafstein (December 4, 1861-December 13, 1922) (born Hannes Þórður) was the first Prime Minister of Iceland. In 1904 he was the first Icelander to be appointed to the Danish Cabinet as the Minister for Icelandic Affairs and was responsible to the Icelandic Althing.
Icelandic stamps of Hannes Hafstein at different ages
HannesHafstein claimed in 1883 that it is based on a true story from the east of Iceland (B396).
If all this should one day turn out to be nothing but unreliable family anecdote, we are left with HannesHafstein's statement that the incident underlying the poem occurred in the east of Iceland.
Hannes is likely to have acquired his information about the poem's origins --- whether true or not --- from Páll Melsteð.