1732 Carl von Linné, Sweden, wrote down in his Lapland excursion diary the rules of the Saami tafl game Tablut.
1811 James Edward Smith, UK, translated the Latin parts of the Linné diary, like the Tablut rules, into English.
The Smith translation introduced some errors, which are in contradiction with the Linné description:
The friendly throne square; the Linné throne square is hostile.
The king being captured from 4 sides everywhere on the board (and this has in some later attempts of reconstructon lead to another error, the unarmed king, to keep up the game balance). The Linné king is armed and captured from 4 sides in the board center and 2 sides everywhere else.
1913 H. J. R. Murray, UK, identified the game described by Linné to be Hnefatafl, based on the Smith translation.
1980 David Brown, UK, made a reconstruction including the errors of the aforementioned works:
King unarmed and captured from 4 sides.
Throne square friendly.
The king wins on the edge. And David Brown increased the board size to 11x11.
Though based on some early translational errors, David Brown obviously did his home work and tested his reconstructed rules thoroughly, because our test tournament found a game balance of 11 defenders' wins per 10 attackers' wins.
David Brown indicates some options to these rules, fx.
The king can be armed.
The king can win in corner. If so, the corner squares are forbidden to other pieces than the king, and hostile to attackers (but not to defenders. And throne square still friendly).
At some point the David Brown rules were adjusted into a version often described on the internet, we call it the "Old Hnefatafl 11x11":
King armed and wins in corner.
All five forbidden squares are hostile to all pieces; the throne, however, only hostile to defenders when empty.
This game works - we measured a game balance of 104 attackers' wins per 100 defenders' wins.
On the way an important David Brown rule was lost and forgotten: "If the attackers surround the king and ALL remaining defenders, then they win, as they have prevented the king from escaping."
2007 the Fetlar Hnefatafl Panel, chairman Peter Kelly, was set up in the Shetland island Fetlar with the object of finding a practical set of rules for using world-wide.
They decided on the above mentioned "Old Hnefatafl" with one modification:
The king cannot be captured on the board edge.
This game, Fetlar Hnefatafl 11x11, works fine - game balance measured to 142 defenders' wins per 100 attackers' wins. The rules have been used for World Championship tournaments in Fetlar 2008, 2009, 2010 and 2013.
From January 2012 Aage Nielsen (Denmark), Adam Bartley (Norway) and Tim Millar (UK) (also supported and commented in the process by other tafl players in the forum) worked on filling in some gaps we perceived in the Fetlar rules:
It is possible for the defenders to build a center draw fort in two moves and thus force a draw.
There is no rule handling repetitions, other than they result in a draw.
This work resulted in a rule set, which is identical to Fetlar but with a few additions:
The lost David Brown rule was reinvented: "If the attackers surround the king and ALL remaining defenders, then they win, as they have prevented the king from escaping."
All repetitions banned and all draws abolished, except for a draw caused by too few pieces on both sides.
The idea of the Fetlar draw fort was continued in the shape of the Exit Fort.
The shieldwall capture, described in a German tafl page, was incorporated. (See
September 2012 the rules were ready, and they were named Copenhagen Hnefatafl 11x11.
The game balance is measured to 136 defenders' wins per 100 attackers' wins. The rules have been used for World Championship tournaments on this site 2013-2022, in Formby, UK, 2014-2016 and in Sutton Hoo, UK, 2015-2016.