The Shieldhall is an old feast hall of dark stone at Castle Black. It is long and drafty, with blackened oak rafters. It is large enough to seat two hundred people, or three hundred if seated close together. However, it is rarely used, as it is dark, difficult to heat, its cellars infested with rats, and its rafters worm-eaten and covered in spiderwebs.
In years past, when the Night's Watch was much larger in number, the Shieldhall was used as a dining hall for the knights of the Watch. When a knight took the black, his shield would be hung on the walls of the Shieldhall, and he would take up the plain black shield of the brotherhood. When a knight died, his shield was removed from the walls, to go to the deceased's pyre or tomb. With hundreds of knights in the Watch at a time, the walls had been hung with hundreds of brightly colored wooden shields. However, as the Night's Watch declined in number, the knights no longer dined separately but instead with the others in the common hall, and the Shieldhall was abandoned. After 200 AC, the Shieldhall was used only infrequently, especially as its dilapidated condition made it unsuitable as a dining hall. By 300 AC, fewer than a dozen faded and cracked shields remained on its walls.
A Dance with Dragons
After letting Tormund's free folk through the Wall, Lord Commander Jon Snow has them gather with the Night's Watch within the Shieldhall, as it can hold at least three hundred people. Jon announces his intention to ride south against House Bolton. He does not order the Night's Watch to fight with him, but asks both wildlings and black brothers alike to join him of their own volition. Most wildlings in the Shieldhall agree to support him, but Jon's decision causes great discontent within the Watch's upper leadership. Shortly after Jon leaves the Shieldhall, he is attacked in a mutiny.
Hundreds of knights meant hundreds of shields. Hawks and eagles, dragons and griffins, suns and stags, wolves and wyverns, manticores, bulls, trees and flowers, harps, spears, crabs and krakens, red lions and golden lions and chequy lions, owls, lambs, maids and mermen, stallions, stars, buckets and buckles, flayed men and hanged men and burning men, axes, longswords, turtles, unicorns, bears, quills, spiders and snakes and scorpions, and a hundred other heraldic charges had adorned the Shieldhall walls, blazoned in more colors than any rainbow ever dreamed off.—Thoughts of Jon Snow