Arrange a massive battle between Vikings (pagan Scandinavians, if not the OTL Vikings) and Mongols.
Bonus points if the Vikings are Danes or Norwegians, not Swedes, Geats, or Kievan Rus, and the Mongols are proper Mongols, not confederated peoples like Tatars and Uzbeks.
Additional bonus points if this battle occurs in Asia, not Europe.
Even more bonus points if it occurs in North America or Africa.