In early Indian chaturanga ( 500–700), the king could be and this ended the game. Persian shatranj (c. 700–800) introduced the idea of warning that the king was under attack (announcing "check" in modern terminology). This was done to avoid the early and accidental end of a game. Later the Persians added the additional rule that a king could not be moved into check or left in check. As a result, the king could not be captured, and checkmate was the only decisive way of ending a game.