King Théoden rules the kingdom of Rohan in The Lord of the Rings film trilogy.
Rohan is a land of horse-lords located north of Gondor. Its people are renowned for their cavalry, and horses are central to the kingdom’s identity, military strength, and culture. Théoden rules from Meduseld, the Golden Hall of Edoras.
In The Two Towers, Théoden is weakened and manipulated by Gríma Wormtongue, who serves Saruman. Gandalf helps free the king from this influence. Théoden then leads his people through the crisis caused by Saruman’s invasion, including the defense of Helm’s Deep and the later ride to Gondor’s aid.
Rohan is often confused with Gondor because both kingdoms fight Sauron’s forces and are central to the final battles. Gondor is ruled from Minas Tirith, while Rohan is the horse-centered kingdom whose riders answer the famous call from Gondor.