This game has been around for centuries in India, Persia and the Near East. In the first centrury it was given the name “tabula” (a table or “tables”). For a long time, it was esteemed as highly as chess. The crusader knights carried it on their campaigns.
In the middle ages in England it acquired its present name – gammen being “game” in Middle English, and “back” because in certain circumstances, the pieces are obliged to go back and reenter the board.
