Where did the golf term 'fore' come from?

As today players many years ago had caddies, and each caddy had a "forecaddy", the forecaddy would assist the caddy. The forecaddy would stand out in the fairway and wait for the balls to be hit from the tee, so they could be found. As soon as the player hit the ball, the caddy would shout "fore", a shortening of the Word forecaddy, to let him know the ball was coming.