Battle of Helm's DeepBattle of Helm's Deep (3019 T.A.) - Saruman's attempt to conquer Rohan.

 

"Even as they spoke there came a blare of trumpets.  Then there was a crash and a flash of flame and smoke.  The waters of the Deeping-stream poured out hissing and foaming: they were choked no longer, a gaping hole was blasted in the wall.  A host of dark shapes poured in.  'Devilry of Saruman!' cried Aragorn.  'They have crept in the culvert again, while we talked, and they have lit the fire of Orthanc beneath their feet.  Elendil!  Elendil!' he shouted, as he leaped down into the breach; but even as he did so a hundred ladders were raised against the battlements.  Over the wall and under the wall the last assault came sweeping like a dark wave upon a hill of sand." ~The Two Towers, Book III, chap. 7 (Helm's Deep)