Hnefatafl is an ancient board game that was very popular during the Viking Age in Scandinavia. A number of variants of Tafl, or "Table" games existed, but Hne-fatafl ("King's Table") was the one it usually referred to. Hnefatafl was known in Scandinavia before 400 A. D. and was carried by the Vikings to Greenland, Iceland, Ireland, Britain, Wales and as far east as the Ukraine. The Saxons had their own variant, derived from a common Germanic Tafl game, which was apparently the only board game known to them prior to the introduction of Chess.
There are many articles online about Hnefatafl. Here's a short list of just a few:
This game was designed and programmed by Nadya Primak in 2015. You can see more of her work at www.nadyaprimak.com