Rohan was the fictional kingdom ruled by Théoden in J.R.R. Tolkien’s The Lord of the Rings.
Rohan is a land of horse-breeders and riders located north of Gondor. Its people are known as the Rohirrim, and its royal house is connected to the Éothéod, an earlier Northman people. Théoden is king when the War of the Ring reaches Rohan.
The kingdom faces a crisis after Théoden falls under the influence of Gríma Wormtongue, who serves Saruman. Gandalf helps restore the king’s strength, and Théoden then leads his people in the defense of Helm’s Deep and later rides to Gondor’s aid.
Rohan and Gondor are neighboring allies, not alternate names for the same realm. Gondor lies to the south, while Rohan’s identity is especially tied to horses, open grasslands, and the fortress of Helm’s Deep.