The Battle of Helm’s Deep, as written by JRR Tolkien in The Two Towers and then visually depicted on screen in the cinematic adaptation, is without question one of the most iconic battles ever written or filmed. In the battle, roughly 400 Rohan soldiers and 100 elves defend Helm’s Deep under the command of King Theoden and Aragorn against 10,000 Uruk-Hai man-orc hybrids under the command of the evil wizard Saruman. Helm’s Deep is a fortress that lead the way into a cave system known as the Hornburg deep in the mountainside, where unarmed civilians were hiding.
The Uruks sustain enormous losses but eventually succeed in breaching through the walls and flooding the fortress. The surviving defenders are on the verge of being annihilated, and decide to launch a suicidal horse charge in a last ditch attempt to kill as many of the enemy as possible. Just then, Gandalf and Eomer arrive with reinforcements of roughly 3,000 cavalry, who rout the remaining Uruks.