13th century, Old Norse.
'The troll inside this barrow will kill us all!' they warned.
'Don’t steal from me,' said a Hebridean farmer. 'Sail south for six days and you will come to the barrow of a man who once ruled over Gaul and was buried with all his wealth.'
The vikings sailed for six days and came to the burial mound of Thrain. 'Does anybody fancy coming in with me?' asked Hromund. Nobody did. 'The troll inside this barrow will kill us all,' they warned.
Hromund lowered a chain and descended into the barrow. Inside, he found the occupant sitting on a chair in front of a fire talking to himself, with all his wealth strewn around him. He had become so old, and was so skilled in sorcery, it is said, that he had gone voluntarily into the burial mound whilst he was still alive.
Story fragment recounted from: the medieval Icelandic saga of Hromund Gripsson, translated by Gavin Chappell, chapters 3–4.
Icelandic saga – Wikipedia
Legendary sagas – Wikipedia
Hrómundar saga Gripssonar – Wikipedia
Troll – Wikipedia
The Saga of Hromund Gripsson – translated by Gavin Chappell: New Northvegr Center