Around the year 1000 A.D. a group of Vikings, led by Leif Ericsson, landed on the northern tip of what is now Newfoundland, Canada, and wandered south to warmer and more hospitable places.  They called the newly-discovered land Vinland, meaning Wineland, for the grapes they found there, and they traded their own goods with the natives for food and timber to sustain their colony on Greenland. Leif's brother Thorvald led a second voyage to Vinland, but instead of trading with the natives, he plundered their resources and killed those natives who resisted.  The surviving natives retaliated: they killed Thorvald and most of his crew and drove the survivors out of Vinland  They subsequently repelled two more expeditions; so the expeditions were terminated and the Greenland colony eventually had to be abandoned.  In this story, a Seer predicts these events and resolves to alter them with the intention of turning Vinland into a sanctuary for magical people, who, he predicts, will be persecuted by Muggles several centuries later.