Eorl's father Léod was a tamer of horses among the Éothéod, who captured this wild white horse while it was still a foal. He tried to tame it himself, but when he attempted to mount it, it threw him and escaped. So Léod died, leaving a sixteen-year-old son, Eorl. Eorl hunted the white horse, found it, and demanded that it give up its freedom in payment for the death of his father. The horse agreed, and took the name that Eorl gave it: Felaróf, a name said to mean 'very valiant' or 'very strong'.
It was on Felaróf that Eorl rode to the aid of Gondor and earned a famous victory, one that would lead Steward Cirion to grant them the wide empty land of Calenardhon, which would come to be called Rohan. For more than thirty years afterwards, Felaróf had the freedom of those wide grasslands, but a new invasion of Easterlings saw Eorl ride to battle once again. In the Wold, the far northern reach of Rohan, Eorl and Felaróf met their ends, and were laid together in a mound raised outside the gate of Edoras.
Felaróf was a very remarkable horse indeed. It is even recorded that he could understand the speech of Men. He gave rise in turn to a race of wonderful horses, the Mearas, who according to tradition could only be ridden by the Lords of the Mark, Eorl's descendants. It was from this line that Gandalf's horse Shadowfax came, making him a descendant of Felaróf himself.