At Delphi, the Oracle gave cryptic answers to queries in such a way that events that turn out badly can always be blamed on mis-interpretations of the answers. One such was a Greek king in Asia Minor who asked if he should start a war against the Persians. The Oracle's answer: "In such a war, a great kingdom will be destroyed". So, he went to war, since he thought the Oracle predicted a Persian defeat. Instead, he lost, and his kingdom was destroyed. You see, his was a kingdom, that of the Persians was an empire. Hee, hee!
We had a look at where this Oracle resided. It was a hole in the ground from which magical fumes emanated. The priestess would breathe the fumes, go into a trance, and then pronounce the Oracluar wisdom. Trouble was, the words were so garbled that only the priests could interpret them, for a suitable fee of course. The funny thing was that even the traditional enemies of the Greeks, e.g. the Persians, would come and consult the Oracle. Wonderful ecumenism in those days!