An Éored was a division of the Rohirrim consisting of mainly one hundred and twenty riders. The word "Éored" actually was used by the Anglo-Saxons to denote a division. Loosely speaking it referred to any subdivision of the Rohirrim cavalry that was functioning under one commander, and the number of riders fluctuated considerably depending on the situation. For example, during the Battle of the Pelennor Fields, the army of the Rohirrim was divided into 3 Éoreds of roughly 2,000 riders each, commanded by Éomer, Elfhelm, and King Theoden himself. In the ensuing battle, 2,000 riders, including Theoden, were killed (one Éored was not annihilated, these were combined losses for all 3 Éoreds). Demonstrating the fluidity of the subdivision, the surviving force was then simply reorganized into 2 Éoreds: one which stayed to aide in the defense of Minas Tirith, and the other which Éomer led in the march to the Black Gate as part of the combined Army of the West under Aragorn.