Alea evangelii

Alea evangelii is from the tafl family of games. The original name of the game is unknown. Alea evangelii is the first words of the twelfth-century Corpus Christ College manuscript 122, commonly known as Corpus Irish Gospels, which contains a description of the game. The game is believed to represent a naval battle and is played on a 18 x 18 game board. The description of the game states that it was invented at the court of King Æthelstan of England (924–939).

Each of the four corners and borders of the diagram is assigned to one of the four Evangelists. 67 pieces are derived from the Eusebian Canons: each Canon defines a number of pieces corresponding to the square of its number of columns. Pieces defined by a specific canon are grouped together on the board: such groups are labeled by a cross and the number of the corresponding canon.

Four more pieces are painted in red (all the others are painted in black) and in the manuscript are mentioned as "different men" (varios viros): two of these four pieces are assigned to the Evangelist John (N14, F6), the other to Mark (N6, F14). The four “different men” are also labeled on the board as related to the passion of Christ.[8] One of the black pieces (E13) is referenced in the manuscript as "the primary man" and "belongs to none of the evangelists"; it represents "the Unity of the Trinity", the one purpose of the four evangelists. Finally, "the figure 1 in the middle of the alea signifies the indivisible substance of the Trinity, or the supremacy of the first canon".[6]

The 16 pieces of Canon I form the diamond at the center of the board. Canons II, III and IIII, together with the four "different men" and the "primary man", form the circle surrounding the central diamond. Canons V, VI, VII, VIII, IX are organized horizontally along the lines of the board. The four pieces corresponding to each of the four Evangelists in Canon X are placed in the four quadrants of the board (C14, Q14, C6, Q6).

The manuscript mentions the existence of attackers and defenders, but the two sides are not differentiated on the diagram, which only presents the details of how the pieces are assigned to the four evangelists according to the Christian allegory which is the main subject of the text. In other tafl games the goal of the attacker is to capture the king and the goal of the defender is to make the king escape from the board, it has been assumed that this is the case also with the game on which the Alea Evangelii moralization was based.

Games of the tafl family only have two kinds of pieces: a king that occupies the center of the board in the initial layout and a number of ordinary pieces divided between attackers and defenders with a 2:1 ratio. The "dukes and count" that appear in Alea Evangelii do not seem to fit this simple scheme. It is tempting to suggest that on his travels, perhaps in Rome, Israel may have heard of the new game just beginning to circulate in Europe, chess, with its comites, milites, and other pieces, and borrowed the idea of different ranks from that game.