Battle of Helm's Deep
Helm's Deep, with its fortress the Hornburg, becomes the refuge of some of the army of Rohan, the Rohirrim, under King Théoden, from assault by the forces of Saruman.
He noted further that his walking forest was partly a response to Shakespeare's Macbeth, which tells of the coming of "Great Birnam Wood to high Dunsinane hill".
In The Lord of the Rings, the Dwarf Gimli, who like all dwarves is well versed in geology, horrified that the caves are used only as a refuge, describes them lyrically as: immeasurable halls, filled with everlasting music of water that tinkles into pools, as fair as Kheled-zâram in the starlight.
then […] gems and crystals and veins of precious ore glint in the polished walls; and the light glows through folded marbles, shell-like, translucent as the living hands of Queen Galadriel.
There are columns of white and saffron and dawn-rose […] fluted and twisted into dreamlike forms; they spring up from many-coloured floors to meet the glistening pendants of the roof: wings, ropes, curtains fine as frozen clouds; spears, banners, pinnacles of suspended palaces!
[T 7]The mouth of the gorge, Helm's Gate, was closed by the battlemented Deeping Wall, 20 ft (6.1 m) tall, and wide enough for four men to stand abreast, with a culvert for the Deeping-stream which flowed down the valley.
[3] The valley was named after King Helm Hammerhand of Rohan, when he and his people sought refuge from the invading Dunlendings under Wulf during the winter of T.A. 2758–2759.
[4] The enemy, Saruman's army, consisted of at least 10,000 Orcs and men, most marching from Isengard to Helm's Deep, and others heading to the Fords of Isen.
[T 2] The forces of Saruman, common Orcs, large Uruk-hai, "half-orcs and goblin-men", and Dunlendings (Men of Dunland), arrived at Helm's Deep on a stormy night.
Orcs crept into the culvert and made a breach in the wall using a "blasting-fire" from Orthanc, perhaps "a kind of gunpowder";[2] Saruman's army rushed in.
[T 2] After the battle, the Dunlendings were given amnesty by Erkenbrand and allowed to return home (much to their surprise, since Saruman had told them that the men of Rohan would burn all survivors alive).
An indecisive battle ensued, after which the Rohirrim camped for the night, and woke to see the enemy surrounded and destroyed by a wood that had appeared overnight.
When Cirion, Steward of Gondor, gave Calenardhon to the Éothéod, Aglarond was transferred into the care of the Rohirrim, who named it Súthburg ("South-fortress" in Old English).
[T 12] Tolkien noted in a letter that he had created walking tree-creatures partly in response to his "bitter disappointment and disgust from schooldays with the shabby use made in Shakespeare's Macbeth of the coming of 'Great Birnam Wood to high Dunsinane hill': I longed to devise a setting in which the trees might really march to war".
[T 13] The Tolkien scholar Tom Shippey calls it a "shock" that the battle is decided by having a forest of Huorns destroy Saruman's army of Orcs.
[5] Charles Oughton likens the Battle of Helm's Deep to Livy's account of Horatius Cocles's heroic defence of Rome's Pons Sublicius bridge.
[9][11] In the film, 10,000 of Saruman's Uruk-hai (with no Orcs of other races, Dunlendings or wargs to accompany them) lay siege to the fortress, defended by around 300 Rohirrim.
The defenders suffer heavy losses, but hold out until dawn, when Gandalf arrives with 2,000 riders led by Éomer, who turn the tide of the battle and rout Saruman's forces.
