By the time of the War of the Ring, Théoden had been king for nearly 40 years and was becoming old and tired. He was increasingly misled by his chief adviser Gríma (or Wormtongue as most others in the Mark called him), who was secretly in the employ of Saruman the White.
When Gandalf the White, Aragorn, Legolas, and Gimli appeared before him, Théoden initially rebuked Gandalf’s advice to resist Saruman, but after being released from the effects of Gríma, he commanded Hama to release his nephew and bring him his sword, and led the Riders of Rohan into battle against Saruman but having found that Saruman’s forces had broken through Rohan’s outer defenses.
“Arise, arise, Riders of Théoden!
Fell deeds awake: fire and slaughter!
spear shall be shaken, shield be splintered,
a sword-day, a red day, ere the sun rises!
Ride now, ride now! Ride to Gondor!”
— Théoden, seventeenth King of Rohan
From the moment those Rohan horns sound a resounding note of hope, to the bone-crunching crash into the lines of Mordor, the Ride of the Rohirrim is four minutes of pure, exhilarating anticipation and spectacle.
Theoden’s grim soliloquy at Helm’s Deep in The Two Towers and inner monologue on the ride to Minas Tirith in this film had already established him as accepting his doom. And “the doom of men”. When he and his followers arrive over the crest of a hill, and see the city – much like Sauron’s eye – “wreathed in flame”, it might be supposed this would only deepen that despair. And yet on the Pelennor Fields, in the face of the vast and formidable Mordor hordes, Theoden’s resigned acceptance shifts into something far more defiant, brave and heroic. ￼