Lost Norse of Greenland fuelled the medieval ivory trade, ancient walrus DNA suggests

New DNA analysis reveals that, before their mysterious disappearance, the Norse colonies of Greenland had a "near monopoly" on Europe's walrus ivory supply. An overreliance on this trade may have contributed to Norse Greenland's collapse when the medieval market declined. The very thing which gave the society its initial resilience, may have also contained the seeds of its vulnerability - James Barrett The Icelandic Sagas tell of Erik the Red: exiled for murder in the late 10th century he fled to southwest Greenland, establishing its first Norse settlement. The colony took root, and by the mid-12th century there were two major settlements with a population of thousands. Greenland even gained its own bishop. By the end of the 15th century, however, the Norse of Greenland had vanished - leaving only abandoned ruins and an enduring mystery. Past theories as to why these communities collapsed include a change in climate and a hubristic adherence to failing farming techniques.