The Rohirrim are famous as skilled horsemen and renowned masters of horse breeding. Among the horses of the Rohirrim are the famed Mearas, the noblest and fastest horses who have ever roamed Arda; Shadowfax was the greatest of all Mearas. There were very few Mearas left in Middle-earth at this point, but there were enough that a breeding population was present. The armies of Rohan are almost exclusively cavalry, divided into irregular units termed éoreds. Rohan’s foot-men armies were more of a very well trained militia called upon in times of war, the militia of Rohan wielded wooden shields of all sizes and used four weapons: longswords, short bows, axes, and longspears. The actual standing infantry army was relatively small with the professional career limited to the royal bodyguard of Edoras. Royal Guard of Rohan of Edoras were the elite soldiers of Rohan and fought on foot as well as on their horses, they have heavy plate-armour and wield large round wooden shields, their weapons were mostly the longspears which were used for thrusting or throwing at their enemies, they also carried longswords for close combat in the event that they lost their spear. Their powerful cavalry (the Rohirrim) could cut through almost any infantry lines and cavalry units and turn the tide of battle. The warriors of Rohan used the same weapons as their footmen counterparts when on horseback.
It was because of this close affiliation with horses, both in war and in peace, that they received their now famous name. Rohirrim (or more properly Rochirrim) is Sindarin for “Horse-lords,” and Rohan (or Rochand) meant “Land of the Horse-lords.”