Before chess, there were the ancient Tafl games of the Nordic & Celtic people. Rooted in the same idea of military strategy, but with a less complicated rule set. Due to the less than stellar documentation of these games, there's a number of ways to setup the board, and approach your strategy, but the basics are always the same. Two teams, a king and his guards, and twice as many attackers, on a checkered board, take turns moving their pawns across the board, surrounding one another to remove them from the board. If the king escapes to the edge of the board, the guards win, if the king is captured, the attackers win.