Born in TA 2485, Eorl was the son of King Léod of the Éothéod. When he was 16, his father got thrown off his horse and died. Thirsty for vengeance, Eorl hunted down the horse but when he at last caught him, he did not want to kill such a magnificent animal. So he took Felárof for his own horse.

Eorl became king at a young age, thereby getting his nickname "The Young".

In TA 2510 a messenger called Borondir came to him with a plea from Cirion, steward of Gondor, to help him against the Balchoth, a force of the Easterlings. Eorl quickly gathered a force of 7000 and rode forth. They crossed the Anduin at the North Undeep and assaulted the Balchoth who had driven Cirion back over the Limlight. The Rohirrim broke upon the rear of the enemy and pursued them into Wold.

So great was the fear of the Northmen that the enemy fled in panic and the Rohirrim pursued them into plains of Calenardhon. Thus ended the Battle of the Field of Celebrant in favor of Gondor.

Cirion gave Calenardhon to Eorl as a sign of gratitude and friendship. They swore an oath, known as the Oath of Eorl, at the tomb of Elendil saying that Gondor and the new kingdom of Rohan would be allies. Eorl was Rohan's first king.

In 2512 his son Brego was born. In 2545 Eorl fell in the Battle of the Wold fighting the Balchoth.

Éomer was said to be descended from Eorl through Brego's youngest son Eofor. The Rohirrim were also known by the name Eorlingas, which they took to honour their first king.
Encyclopedia entry originally written by Perathion