Second Battle of Winterfell

The Second Battle of Winterfell, also known as the Battle of the Bastards, is a battle late in the War of the Five Kings. In it, Jon Snow and Sansa Stark retake Winterfell from Lord Ramsay Bolton, the Warden of the North, and restore House Stark's rule over the North in defiance of House Lannister and the Iron Throne.

Surrounded by Bolton men, the Stark-led makeshift force of Free Folk and other minor Northern houses is on the verge of defeat when the Knights of the Vale arrive in time to smash through the Bolton phalanx. The battle ultimately culminates in Ramsay's death, the extinction of House Bolton and the restoration of House Stark as the rulers of the North. The fate of the Karstarks and the Umbers remains unknown.

It is depicted in the eponymous episode, "Battle of the Bastards".

Prelude
"A monster has taken our home and our brother. We have to go back to Winterfell and save them both!"

- Sansa Stark to Jon Snow

With the death of Robb Stark and most of his bannermen during the Red Wedding, House Bolton is named the new ruling Great House of the North by House Lannister. However, to cement their hold on the North following the murders of Joffrey Baratheon and Tywin Lannister, they betray the Lannisters and secure a marriage alliance through Lord Petyr Baelish between Sansa Stark, formerly the Lannisters' hostage, and Ramsay Bolton, Lord Roose Bolton's recently-legitimized bastard son. With help from the Boltons' prisoner, Theon Greyjoy, Sansa escapes her home during Stannis Baratheon's ill-fated attack on the castle and flees to Castle Black with Brienne of Tarth and Podrick Payne, where she reunites with her bastard half-brother, Jon Snow, who was on the verge of leaving the Night's Watch following his death and resurrection.

With Sansa's escape and Roose Bolton having recently sired a son with his new wife, Walda Bolton, Ramsay's position as Roose's heir is left in doubt. In order to secure his position, Ramsay murders Roose and has his stepmother and newborn half-brother mauled to death by his hounds, making him the new head of House Bolton, Lord of the Dreadfort, Lord of Winterfell and Warden of the North.

Sansa urges Jon to help her retake Winterfell from the Boltons. Jon, wary from fighting, is reluctant at first, but agrees when they receive a letter from Ramsay, revealing he has killed his father and is holding their brother, Rickon Stark, hostage, and demanding Sansa's return on threat of murdering the wildlings and Rickon, before having Sansa gang-raped, and Jon himself mutilated and killed.

Raising an army
"There are more than three other houses in the North: Glover, Mormont, Cerwyn, Mazin, Hornwood. Two dozen more. Together they equal all the others. We can start small and build."

- Jon Snow

With the Karstarks and Umbers having declared for Ramsay due to their anger at Robb and Jon, respectively, Jon and Sansa are forced to recruit the meager forces of the minor Houses to aid them. They are successful in persuading the Free Folk, House Mazin, House Hornwood, and House Mormont to join them, while Robett Glover, head of House Glover, refuses to declare for them, citing both his hatred for the wildlings and his anger at Robb for having failed to protect them from Balon Greyjoy's invasion of the North. Sansa sends Brienne to the Riverlands to treat with her great-uncle, Brynden Tully, who is under siege at Riverrun. Unfortunately, Brynden refuses to leave his home and is later killed when the castle falls to House Frey and House Lannister. Brienne and Podrick are able to escape through the river.

After only being able to recruit a small number of minor houses, they are still heavily outnumbered, Jon is adamant that they attack Winterfell as soon as possible to prevent Ramsay from gathering more men or the weather turning against them, like it did for Stannis Baratheon. Sansa, however disagrees, instead opting to try and recruit more houses. When Jon refuses to listen to her, Sansa secretly writes a letter calling for help without telling Jon.

Parley and Recess
"Thousands of men don't need to die. Only one of us."

- Jon Snow to Ramsay Bolton

On the day before the battle, the Stark leadership agrees to parley with the Boltons. Ramsay immediately offers terms for Jon's surrender, claiming that his men will not be harmed, he will be pardoned for deserting his post as Lord Commander of the Night's Watch, if Sansa is given to him and Jon bends the knee and acknowledges him as the Lord of Winterfell and Warden of the North. Jon rejects this, knowing that Ramsay has broken his own surrender terms multiple times in the past, and instead opts for a different solution to save both the armies; single combat to determine the fate of the North. This prompts Ramsay to reject Jon in turn, as he has heard that the son of Eddard Stark was the best swordsman in the North, and that he knows that his army was more numerous and better equipped than Jon's. Jon's retorts by pointing out that Ramsay's army is built on shaky loyalty, whereas his own knew that their leader would live and die for them. This angers Ramsay, and prompts him to threaten to kill Rickon if Jon would not surrender. It is at this moment Sansa questions if Ramsay even has their brother, which is responed to by Smalljon Umber pulling out Shaggydog's severed head and throwing it at their feet. Sansa then interrupts Ramsay, claiming that he will die tomorrow and that he should get a good night's rest. Ramsay then threatens Jon some more before leaving.

At the Stark camp, plans are drawn up for the coming battle. Knowing that Ramsay's numbers are superior, they will instead bait him into a double envelopment, using his recklessness and anger against him. After Davos, Tormund, and the rest of the lords are dismissed for the evening, Sansa approaches Jon, furious for not being on the council on the matter and criticizing his plan, claiming that Jon doesn't know how Ramsay's mind works, how he likes toying with people. The argument eventually devolves into a shouting match, with Jon claiming that even if they should lose the battle, he would still be around to protect Sansa. Sansa replies that no one can protect her or anyone now, jaded by years of lies and falsehoods.

Meanwhile, Davos and Tormund take a walk out into the camp, comparing their experiences serving Stannis and Mance, respectively, and the ultimate futility of believing in kings. After some banter, Davos walks up the hill to where he spots a funeral pyre. Spotting and picking up the toy stag he gave to Shireen before Stannis' ill fated attack on the Boltons, he comes to the conclusion that Melisandre must have sacrificed Shireen to the Lord of Light.

Melisandre herself is in her tent when approached by Jon, who immediately asks her not to resurrect him again. She replies that she has no power to do so; she can only utilize what the Lord has given her, and that he was resurrected for a reason. What that reason is, no one knows.

The Battle
The battle begins with the Stark forces deployed near a treeline, to prevent themselves from being taken unawares from behind. Across the field is the much larger Bolton army, using burning flayed corpses in an effort to demoralize the Stark troops. Ramsay himself trots out on his horse to the front of the formation, bringing along a prisoner; Rickon Stark himself. Ramsay acts at first as if he will slit Rickon's throat, but instead cuts his bonds and delightfully insists that he play a game; run to Jon whilst dodging his arrows. Rickon immediately starts running in a straight line toward Jon, while Ramsay shoots and misses with a war bow. Just when Rickon is about to reach Jon, however, Ramsay's final shot hits the young lord straight in the heart, which kills him almost instantly.

Enraged and maddened with grief, Jon charges full tilt at the Bolton forces, who immediately proceed to loose their arrows on him. Alarmed, Davos orders in the Stark cavalry to charge in after their commander, with the infantry closely following behind. His horse shot out from underneath him, Jon prepares for his last stand by drawing Longclaw and facing the Bolton cavalry seemingly alone. He is saved by the timely arrival of the Stark cavalry, and the battle becomes a bloody storm of swords. Men fall in battle so quickly that they begin to form small hills of the dead.

Ramsay orders his own archers to fire on both the Stark forces and their own cavalry, while Davos refrains from doing the same. The arrows fell both Stark and Bolton men, and soon the small hills become a wall of the fallen, which is exactly what Ramsay intends. Davos joins the fray, temporarily stemming the tide along with Wun Wun and Tormund, but are soon surrounded by a pike phalanx led by Lord Umber, who shouts "Who owns the North? Show me!".

The phalanx acts as a noose, tightening around the beleagured Stark men who by now are dying in droves. As they retreat toward the wall of dead, they trample the wounded and squeeze so tightly in the confined space that they are unable to properly move. Jon is barely able to save himself from being crushed to death.

Just when all hope seems lost for the Starks and Free Folk, however, a war horn sounds off in the distance. Around the bend appears a large mounted host of the Knights of the Vale, led by Lord Baelish and Lady Sansa. The newly arrived Arryn reinforcements quickly turn the tide in favor of the Starks, wiping away Ramsay's phalanx while Tormund kills the Smalljon in a brutal duel. Ramsay, now without a fighting force, decides to retreat to Winterfell to hopefully hold out in a siege.

His plan goes awry, however, when Wun Wun breaks down the main gate, allowing the Starks and Arryns to pour through. They kill any and all Bolton men remaining in the castle. Wun Wun collapses to his knees, after being hit by arrows, bolts, and javelins. Before Jon can comfort his old friend, however, Ramsay puts an arrow through the giant's eye, killing him. Ramsay, not knowing when to give up, taunts Jon, saying that he finally accepted his single combat proposal. Jon quickly grabs a shield from a fallen Mormont soldier and proceeds to block Ramsay's arrows a total of three times, all the while advancing. When he reaches the last of the Boltons, he immediately knocks Ramsay to the ground with his shield, then proceeds to beat him savagely, intent on avenging his family at long last. He stops only when he catches Sansa looking at him. Ramsay is immediately put in chains by the Starks, and the Flayed Man banners drop to the ground in a clattered heap while the Direwolf's Head is raised above Winterfell for the first time in three years. This brings an end to the Boltons' rule of the North and a decisive victory for House Stark and its allies.

Aftermath
"Your words will disappear. Your House will disappear. Your name will disappear. All memory of you will disappear."

- Sansa Stark to Ramsay Bolton

The victory, while a decisive one for the Starks, was not without great cost. Out of Jon's original force of 2,400 men, perhaps only 400 survived. What is worse, the heir apparent to Winterfell, Rickon, was now dead, leaving the newly restored Great House in a precarious state. Jon orders Rickon to be buried next to their father, while Sansa decides to visit Ramsay in his new cell; the dog kennels.

Upon seeing Sansa, he mocks her one last time, telling her that she will always have a part of him inside her. She throws back the insult by pointing out that very soon, the legacy of himself and his house will be forever erased from history, as Ramsay now notices his hounds coming closer to him. Scoffing, the former Lord of Winterfell tells her that his hounds were loyal to him, to which she reminds him that he starved them for seven days. As to prove her point, his alpha hound does not respond to his command to heel, and instead proceeds to savagely maul his face. As the bastard of Roose Bolton is devoured by his own dogs, Sansa turns and walks away, savoring the sounds of her husband's demise as she smiles.

Stark forces
Tormund Giantsbane, a chieftain in the Free Folk army, has told Jon Snow that he commands 2,000 fighting wildlings. Furthermore, the Starks have gathered 62 Mormont soldiers, 200 Hornwoods and 143 Mazins. This brings Jon's total host to an army of around 2,400 men, a giant (Wun Wun) and a direwolf (Ghost). Most of the soldiers are infantry, causing a disadvantage against the Bolton forces.

Bolton forces
Ramsay Bolton is rumored to command some 5,000 Bolton men, although possibly weakened after the Battle of Winterfell against King Stannis. The Umbers and the Karstarks possibly have the same numbers, but this has never been made clear.

At the parley one day before the battle, Lord Ramsay states that he's got 6,000 men. It is unknown how many of those men are Bolton soldiers and which part consists of Umber and Karstark forces. However, Ramsay does make clear that he outnumbers Jon's army two to one.

Arryn forces
Earlier in the series, we learn that the Arryn forces are approximately equal to the Stark and Tully forces, which means that Lord Petyr Baelish commands an army of 20,000 men or maybe more. It is left unclear whether Lord Baelish has marched all of the Arryn soldiers into battle, but as the force consists solely of cavalry, this is unlikely. Regardless, the force is more than enough to wipe out the remaining Boltons with ease.

In the books
In the A Song of Ice and Fire novels, no such battle has taken place yet. The fifth and most recent novel, A Dance with Dragons, ends in the first stages of Stannis Baratheon's attack on Winterfell. Given that season six onward is based on an outline of what will happen in future novels, the battle, or a different version of it, rather, may take place in either The Winds of Winter or A Dream of Spring.