Eorl was the lord of the Éothéod, a people of horse-breeders who lived in the north of the Vales of Anduin. His father Léod was killed when he tried to tame a wild horse, and the horse, the great Felaróf, was in the end tamed by his son, who was then a young man. Eorl rode him all his life.1
In the year 2510, the Balchoth, an Easterling people, with the help of Orcs, swept over the lands of Calenardhon and fell on the armies of Gondor at the Field of Celebrant, where the army of the north was nearly destroyed. Cirion, the Steward of Gondor, had sent to the Éothéod for help. Eorl rode south and came to the field in time, and the Riders of the Éothéod broke the Easterlings and drove them into the river.1,2
In gratitude Cirion gave the lands of Calenardhon, then largely empty, to Eorl and his people. Eorl swore the Oath of Eorl, a bond of friendship and mutual aid between Gondor and the new realm of the Mark, and was crowned the first King of Rohan. The oath was kept five hundred years later, when Théoden answered the call of Minas Tirith.1
Eorl fell in 2545 in battle against Easterlings in the Wold, and his son Brego succeeded him and built Meduseld.1,2
Sources
Citations name the chapter rather than the page, so they work in any edition. The colour of each note shows what kind of source it is.
- Appendices Tolkien's own appendices to The Lord of the Rings.
- Appendices The Lord of the Rings, Appendix A, II, “The House of Eorl”
- Appendices The Lord of the Rings, Appendix B, “The Third Age”