1599, Cry 'Havoc,' and let slip the dogs of war — Shakespeare, Julius Caesar
1608, Do not cry havoc, where you should but hunt— Shakespeare, Coriolanus
1961 Aug,George Steiner,“Homer and the Scholars”, inThe Atlantic Monthly, page 77:
War and mortality cry havoc, yet the center holds. That center is the affirmation that actions of body and heroic spirit are in themselves a thing of beauty, that renown shall outweigh the passing terrors of death, and that no catastrophe, not even the fall of Troy, is final.
Etymology
From the Anglo-Norman phrase crier havok(“cry havoc”) a signal to soldiers to seize plunder, from Old Frenchcrier(“cry out, shout”) + havot(“pillaging, looting”).