"There was a man called Kotkel, who had only recently arrived in Iceland. His wife was called Grima. Their sons were Hallbjorn Sleekstone-Eye and Stigandi. These people had come from the Hebrides. They were all extremely skilled in witchcraft and were great sorceress."
-Laxdaela Saga

"Everthing in this description..suggests that this is a nest of witches born to the trade."
-Dr. Stephen Mitchell, commenting on the above verse