Rochirrim

Gondor was saved from invasion in III 2510 by the intervention of their ancient allies, the Men of the Éothéod. At that time dwelling in the far North, their chieftain Eorl had nonetheless led his warriors on a long Ride southward, and defeated invading Balchoth at the Battle of the Field of Celebrant. In gratitude, Steward Cirion granted Eorl and his people a new land, a wide green province of Gondor named Calenardhon.

Eorl's people knew themselves in their own tongue as the Éothéod, the 'horse-people', but after they settled in Calenardhon, they gained a new Elvish name, originally devised by Hallas, the son of Steward Cirion. This new name was based on the word éoherë, a word from the tongue of the Men of the Éothéod for their entire mounted force, and meaning 'horse-host'. Hallas rendered this into Elvish as Rochirrim, from Elvish root words for 'horse', 'lord' and 'people'. In full the Elvish name therefore meant 'people of the horse-lords'. Similarly, Hallas gave a name to the land newly settled by these Rochirrim, which he called Rochand or 'horse-land'.

Hallas' new names were quickly adopted in Minas Tirith, where many of the populace understood Elvish, and even came to be used among the newly settled Northmen, whose own language was suited to their sounds. Many of the people of wider Gondor, however, only spoke the Common Tongue, and for them the -ch- sound in the new name was difficult to pronounce. Thus over time the name Rochirrim evolved in common use to become Rohirrim, the name that would be borne by these people to the end of the Third Age and beyond.