Fragments of walrus tusks unearthed in 2007 were traced back to Greenland, indicating that trading routes in the Middle Ages were more advanced than previously thought.
I was not surprised by this, since I knew something about the life of Harald Hardrada. He was King of Norway from 1045 to 1066. He also claimed both the Danish and English thrones, the latter ending very badly. Before becoming King of Norway he was a mercenary in Kyivan Rus’ and in the Varangian Guard.
As with much of the history I know, most of what I know about King Harald came ultimately from the world of science fiction and fantasy. Poul Anderson wrote extensively in those genres, but also did some historical fiction, sticking closely to the historical record. In particular, he wrote three books about Harald Harald Hardrada, The Last Viking Trilogy: The Golden Horn, The Road of the Sea Horse, and The Sign of the Raven
Reading these, I was struck by how interconnected Northern Europe was, from England to Kyiv, thanks to the Vikings. Anderson emphasized this, and my subsequent non-fiction reading has confirmed it. Looking further west, Iceland was initially settled by Norwegians. Greenland was in turned settled from Iceland. The Norse settlements in Greenland eventually failed, but in the 12th century they were doing well. The export of walrus tusk ivory was an important part of their economy. The exports would have gone to Scandanavia via Iceland, from which it is easy to imagine them making their way to Kyivan Rus’.