Source: Book 'Board & Table Games I' by R.C. Bell.
 
Object: White wins if four of his men (Hunns) surround the king (Hnefi) orthogonally. Black wins if the Hnefi reaches the border of the board.
 
All pieces move like chess rooks, but the Hnefi only one square. Enemy Hunns are captured by trapping a Hunn between two of the player's pieces on rank or file. A piece may move between two enemy pieces without being captured.
 
Variant 2 : the Hnefi may move up to two squares at a time.
Variant 3 : the Hnefi moves like a chess rook. This is the version I found in a book, but I suspect it to be wrong, since it makes the king too mobile and (imho) gives Black an easy win.
Variant 4 : the Hnefi moves like a chess rook, but is immobilised as long as it is trapped between to enemy pieces on rank or file.
 
Hnefatafl was played in the Middle Ages. It originated from the game Tafl, of which no description has survived.
 
 
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