In those days, there was a magician who could cast a spell on a candle and link that candle to the life of a single person. So long as the candle burned, there was hope.
Those families who had the means engaged the magician to cast this spell when husbands and sons went off to battle. So long as the candle burned, their loved one was still alive. The highest winds would not snuff out the flame. But even on a quiet night, if the soldier died, so too would the flame on the candle die. Those families would know of their loss long before word came to them from the battlefield.