Battle of Castle Black

Mance Rayder knows what happened at the Fist of the First Men and decides the Wall is left almost undefended. Rather than throw everything at it at once, he splits his forces: small climbing parties scale the Wall far from Castle Black, while a larger group strikes east, at the Bridge of Skulls approach through the Gorge.

Lord Steward Bowen Marsh takes the bait. He rides out with the Watch's most seasoned fighters, chasing the raiders past the Shadow Tower and beyond, leaving Castle Black with barely anyone to guard it. At the Bridge of Skulls he meets Weeper and three hundred wildlings; he wins, but the victory costs over a hundred dead brothers and leaves Marsh himself wounded, delaying his return even further.

Styr and Jarl scale the Wall with a hundred Thenn warriors to take Castle Black by surprise from its undefended side. Jon Snow is with them, but after a night at Queensgate he manages to slip away from the group — his brother Bran's direwolf, hidden nearby, gives him the distraction he needs — and reaches Castle Black in time to warn Donal Noye of what's coming.

Noye and Jon organize the defense: archers in the towers, a line of men blocking the wooden stair that switchbacks up to the Wall's top. At dawn the Thenn attack, aiming for that stair — without it, no archers can be placed above — but the brothers hold, helped by folk from Mole's Town, sheltering in the castle after being warned.

When the wildlings crowd onto the oil-soaked base of the stair, the Watch sets it alight. The structure collapses and takes the attackers down with it. The first assault is repelled, but with the stair goes the Watch's fastest way of moving men and supplies up the Wall — from then on, everything depends on the winch cages.

After the failed southern attack, Mance sends everything against the Wall on three fronts. He opens with giants riding mammoths, held off by volleys of arrows; to hide how few defenders they really have, the brothers dress straw dummies as guardsmen and even name them after the dead, a grim joke to pass the time.

Only Mag the Mighty, king of the giants, reaches the gates of the tunnel beneath the Wall. Donal Noye and a handful of men hold them with arrows and spears, disabling the opening mechanism behind them. They kill the attackers, Mag among them, but every defender dies with Noye, who is found crushed beneath the giant, his sword still buried in Mag's neck.

At Maester Aemon's request, Jon Snow takes command of the defense. He beats back attack after attack with archers, catapults and fire arrows, and when Mance's men build an armored ram from felled trees, Jon has water-filled barrels of gravel left to freeze solid, then hurled down to smash it.

With the ram destroyed, Ser Alliser Thorne and Lord Janos Slynt arrive from Eastwatch-by-the-Sea with reinforcements — and old grudges against Jon's family. They take command and lock him in the ice cells beneath the Wall, charged as a deserter.

Slynt sends him to parley with Mance, under an unspoken order to kill him and let the wildlings finish the job. During that meeting Jon learns Mance holds the Horn of Winter, and that he hasn't sounded it only because the Wall's magic is the one thing keeping the Others from following south. Mance gives an ultimatum: yield the Wall within three days, or he'll sound the horn.

Meanwhile King Stannis Baratheon has reached Eastwatch-by-the-Sea with fifteen hundred men and, persuaded by his Hand, Davos Seaworth, that this is where a true king belongs, marches on Castle Black.

The Eastwatch detachment strikes the wildlings first, falls back under counterattack and draws them toward the trees — the whole move is nothing but bait. Trumpets sound and Stannis's cavalry, split into three columns, crashes into the wildling camp: one column shatters Harma Dogshead's men, another breaks Tormund Giantsbane's spearmen, the third is checked by the giants but the other two close the pincer. Archers set the tents ablaze while the Free Folk, outnumbering the attackers but outmatched in steel and heavy horse, come apart.

The wildling army is destroyed or captured, and among the prisoners are Mance Rayder, his wife Dalla, their newborn son, and Dalla's sister Val. It is a complete victory for Stannis and the Watch.

The Watch comes out of the battle with most of its officers dead, between the Fist and Castle Black, and no Lord Commander. Stannis asks Jon what he thinks of his plans: legitimizing him as a Stark and setting him over Winterfell, strengthening the Wall against the Others, resettling Brandon's Gift at the Watch's expense, and using the abandoned castles for his own war for the Iron Throne.

But first he demands the Watch choose its new leader quickly. Samwell Tarly convinces several candidates to step aside in Jon's favor, and Jon stands against Lord Denys Mallister, Cotter Pyke and Janos Slynt. With Mallister's and Pyke's backing — and with the late Lord Commander Mormont's raven landing, providentially, on his shoulder — Jon Snow is chosen as the 998th Lord Commander of the Night's Watch.

In HBO's Game of Thrones, the battle is tightened up: the northern attack and the southern attack — this time led by Tormund rather than Styr — happen at once, and the Watch's forces look far more numerous than in the book.

Sam and Pyp are among those defending the castle; Ygritte kills Pyp during the assault. Defense of the tunnel beneath the Wall falls to Grenn, who dies there facing Mag the Mighty — the role the book gives to Donal Noye.