"Ancestral Voices Prophesying War!"

Context: According to the famous (and very suspect) story recounted by Coleridge, a long poem of some two to three hundred lines came to him during an opium-induced sleep. But after awakening and writing down the opening, he was interrupted, and could remember the rest only vaguely. The uncompleted poem was published finally at the request of Lord Byron. It opens in narrative fashion: "In Xanadu did Kubla Khan/ A stately pleasure dome decree." A highly suggestive description follows with a melange of romantic images: a sacred river, a "lifeless" ocean, savage chasms, a demon lover, fountains, and caves. The poem shifts abruptly into a vision of poetic ecstasy, and then ends. The prophecy of war appears but once in the fragment, and its meaning is only to be guessed at:

Five miles meandering with a mazy motion
Through wood and dale the sacred river ran,
Then reached the caverns measureless to man,
And sank in tumult to a lifeless ocean:
And 'mid this tumult Kubla heard from far
Ancestral voices prophesying war!