The Rohirrim were horse-lords, also known as the Riders of Rohan, and Eorlingas in honour of their first king Eorl. Eorl was revered for taming the noblest and fairest horses of Middle Earth. The Rohirrim were constantly ready for battle, as the fertile, grassy valleys they inhabited were bordered by many enemies. They bore spears and long swords set with green gems, and green shields emblazoned with golden suns. Their helmets were made of silver with horsetails trailing from them and their banners bore a white horse on a green background. They were a fair haired race and wore their long hair braided into golden plaits.
Their home of their kings was Meduseld, the gold roofed feast hall in the royal courts of Edoras set into the hills near the white mountains. The last king Théoden fell under the evil power of Saruman, but Gandalf threw off the enchantment and Théoden again rode with his warriors to fight with Gondor at Helm's Deep, then in the battle of the Pelennor fields. He was crushed by his horse when it reared in fear and was shot with a black arrow by the Lord of the Ringwraiths, despite Éowyn's best efforts to defend him.
The Rohirrim are first encountered in The Lord of the Rings when Aragorn, Gimli and Legolas are tracking a group of orcs who have taken Merry and Pippin. The Rohirrim come across Aragorn and his companions in the fields of Rohan, and reveal that they have slain the orcs, and did not notice the halflings. They lend horses to the three travellers on the promise that once they have finished their quest to find the hobbits they will return to Meduseld, a promise which they honoured before riding forth with the Rohirrim into battle.