Full Muster

A 'muster' referred to the calling together of an armed force, and is used especially (though not uniquely) with reference to the Rohirrim of Rohan. The Riders were organised into three separate musters, each commanded by a Marshal, who would gather to defend against threats to particular parts of the land. Only rarely would the King of Rohan decree a Full Muster, in which all three of these lesser musters would be called, causing the entire military force of Rohan to gather for war.

The basic unit of the military among the Rohirrim was the éored, which dated far back in the history of this people. We have references to éoreds even from the times even before the ancestors of the Rohirrim settled in the northern land of the Éothéod, the place they occupied before migrating to Rohan. In these older times éoreds seem to have been large bodies of riders,¹ though by the time of the founding of Rohan they had become more formalised, and typically contained one hundred and twenty horsemen.

A Full Muster brought all the éoreds together to form a body known as an éoherë, a 'horse host'. The first such muster on record was called by Eorl the Young, when he assembled seven thousand of his followers to make the long Ride to bring aid to the beleaguered land of Gondor. At least by the later reckoning, this number would have required nearly sixty éoreds to ride together into battle. The victory they won at the Battle of the Field of Celebrant saved Gondor from invasion, and in gratitude the Gondorians granted Eorl the land that would become known as Rohan.

The name éoherë for a Full Muster of Eorl's people was rendered into Elvish as Rohirrim (approximately 'host of horse-lords'), and thus the people formerly known as the Men of the Éothéod were commonly named the Rohirrim through the later centuries of the Third Age.

After Eorl's time, we have no record of a Full Muster taking place until the War of the Ring, more than five centuries later, but this does not necessarily mean that no musters were called in that time. We might imagine, for example, that Helm Hammerhand at least attempted to call his éoherë during the invasion of Rohan by the Dunlendings in III 2758. If so, however, neither that nor any other instance has found its way into the histories until the time of Eorl's distant descendant Théoden.

A Full Muster was properly defined as consisting of one hundred éoreds, creating a force twelve thousand strong, though in practice such a force had never been assembled. Eorl on his Ride had led an éoherë of some seven thousand, and when Théoden called a Full Muster during the War of the Ring, he was able to assemble some six thousand Men (or about fifty éoreds). Though this number fell well short of the ideal twelve thousand, it was nonetheless said to have been the greatest force mustered by the Rohirrim since Eorl's time.

In Rohan, the Full Muster was made up from three separate lesser musters, each under the command of its own Marshal: the Muster of the West-mark, the Muster of the East-mark and the Muster of Edoras. The events leading up to the War of the Ring, however, had undermined these arrangements, leaving Éomer as the sole surviving Marshal of the Mark. Prior to the War, Éomer had formally been commander of the East-mark, but Théoden appointed him as First Marshal and chief advisor to the King. Meanwhile Grimbold and Elfhelm took command of the Riders of the West-mark and the East-mark, respectively.

The Full Muster of Rohan during the War of the Ring gathered at Dunharrow in the White Mountains, and set out for Minas Tirith on 10 March III 3019. Its six thousand Riders were led by the King of Rohan himself, Théoden, at the head of his own household éored. Their scouts discovered enemies holding the Rammas Echor to bar their way but, passing instead through the Stonewain Valley, the Rohirrim were able to skirt this threat and come the Pelennor Fields. There they broke into their three lesser musters and rode to the relief of Minas Tirith. With their aid, the Gondorians won the day, though King Théoden was slain in that battle, and Marshal Éomer became King of Rohan in his place.

Though the Full Muster of Rohan saw the only use of that specific name, there were other general musters among other peoples of Middle-earth. The most historically important of these was the Mustering of the Dwarves, in which King Thráin II called on all the Dwarves to join him in avenging the death of his father Thrór at the hands of the Orc Azog. The ensuing War of the Dwarves and the Orcs was fought for nine years, culminating in the dreadful Battle of Azanulbizar in III 2799.

Among the Shire-hobbits, there was a tradition dating back to the early days of their land known as the Shire-muster. One of the duties of the Thain of the Shire was to call this Shire-muster, and gather the Hobbitry-in-arms together when needed. By the end of the Third Age, this had become a purely formal and ceremonial role.²