The use of the white flag to ask for a truce is almost universally recognized today. It arose around the eleventh century in Europe as an emblem of the peace and truce of god when the church attempted to end the blood lust of the nobility by prohibiting private warfare on weekends and during advent and lent. The rules of war governing the uses of white flags are not as rigid as might be supposed. When a commander is presented with this offer of peace, he is not in every case bound to accept it. As flag experts have pointed out, the white flag has often been used as a ruse of war, for even a temporary halt in battle can give an advantage to the side that is losing and an officer under a truce flag can serve as a spy.
History records numerous examples of the betrayal of flags of truce.