Ser Alliser Thorne was the Master-at-Arms at Castle Black, responsible for training new recruits to the Night’s Watch.
After the Battle of Castle Black, Thorne loses the election to become the 998th Lord Commander of the Night’s Watch, narrowly beaten by Jon Snow. The new Lord Commander names him the First Ranger, as a result of his experience and to appease his followers in the Watch. Thorne, however, betrays and leads a mutiny against Jon after the latter led a mission to Hard home to rescue the remaining wildling’s, but after Jon is resurrected, Thorne is arrested and later hanged for his treason.
Ser Alliser Thorne is a member of the Night’s Watch. He is from House Thorne, a noble house of the Crown lands sworn to the Iron Throne. He fought on House Targaryen’s side during Robert’s Rebellion, which ended in their defeat. Like many other Targaryen loyalists, the victorious rebels subsequently gave him a choice between execution or joining the Night’s Watch. He chose the latter.
During the last winter, Thorne and his ranger companions were trapped in a massive winter storm and had to resort to cannibalism to survive. Through seventeen years of able service, Thorne rose through the ranks of the officers in the Night’s Watch to become the master-of-arms at Castle Black, responsible for training new recruits – a task he takes no joy in, as most recruits in recent generations tend to be petty criminals sent to the Wall as punishment.
Thorne sets Jon Snow against his fellow recruits Rast, Pypar and Grenn, and mockingly refers to Jon as “Lord Snow”. Jon beats the other recruits easily, due to his previous training at Winterfell, but is unaware that Thorne, who despises Eddard Stark for the part he played in Robert’s Rebellion, is making him unpopular by emphasising his superiority. Tyrion Lannister advises Jon to take into account the less privileged upbringing of the other recruits and suggests that Jon could befriend them by sharing his skills.
Later, Thorne is disgusted by the obesity and softness of new recruit Samwell Tarly, nicknaming him “Lord Piggy”. He has Rast beat Sam when he will not fight back. Jon convinces the others to refuse to hurt Sam, but when they do, Thorne sees through the ruse and berates Jon. Thorne later confronts Jon and Sam, revealing that he once had to cannibalise the frozen remains of his comrades to avoid starvation during a ranging beyond the Wall in a particularly cold winter. He berates Jon and Sam for their softness, and warns Jon that his “protection” of Sam from the harsh training that he needs will eventually get him killed.
Thorne is pleased when Jon is made a steward, since Jon had hoped to become a ranger like his uncle Benjen Stark. Lord Commander Jeor Mormont takes Jon as his personal steward. Jon believes that Thorne played a hand in him becoming a steward as revenge for defying him, but Sam convinces Jon that this means that Jon will be privy to the inner workings of the Night’s Watch command structure, and that the Lord Commander may actually want to groom Jon for a high position within the Watch.
After Eddard is (falsely) arrested as a traitor, Thorne taunts Jon and calls him “not only a bastard, but a traitor’s bastard”. Jon draws a knife and attempts to strike Thorne but is restrained and punished by being restricted to his quarters. Later, the Lord Commander sends Thorne to King’s Landing with the frozen hand of one of the wights to warn King Joffrey Baratheon and the royal court of the return of the White Walkers. He notes that part of his decision was to keep Jon and Thorne separated for a time.
Upon his return to the Wall, Thorne has been declared the Acting Lord Commander of the Night’s Watch. He is one of the five black brothers to “judge” Jon for his actions during his time with the wildling’s. Jon hides nothing of his actions, neither his murder of Qhorin nor his affair with Ygritte. Thorne disbelieves Jon’s claim that the Half hand wanted to die, but Jon counters that if Thorne was as close to Qhorin as he claims, he would know the fallen brother would have done anything to protect the Wall. Maester Aemon defends Jon on the other charge, pointing out that he isn’t the first to have broken his vow of celibacy. Thorne points out that Jon hasn’t simply visited the whorehouse in Mole’s Town: he has quite literally slept with the enemy.
Jon counters with all the information that he had learned while among the wildling’s, such as Mance Rayder’s strategy of attacking the Wall from the North and the South, and demands that they either kill him or let him go. Aemon tells him that they have no intention of executing him and Jon leaves. Thorne reprimands Aemon for having overruled him but Aemon wryly replies that he can tell who is lying to him, since he grew up in King’s Landing.
Thorne is present when a young boy, Olly, tells the Night’s Watch how a wildling raiding party massacred his village. Most black brothers want to seek revenge and send the wildling’s a message, but Jon and Thorne know better: that is exactly what the wildling’s want, to draw them out of Castle Black and fight them in the open. The black brothers are interrupted by two rangers returning, Grenn and Eddison Tollett, who have escaped the mutineers holed up at Craster’s Keep. Upon learning that the mutineers are still at Craster’s Keep, Jon claims that they must be captured or killed. Thorne initially refuses, but Jon claims that it is to stop the mutineers from revealing the truth of the Night’s Watch’s defences to Mance Rayder’s army if they are attacked, since Jon has previously exaggerated to Mance. Thorne has also given Sam a new derogatory nickname: “Sam the Slayer”, disbelieving his claim that he killed a White Walker with a dragon glass dagger.
Thorne later berates Jon when he sees him helping Grenn train recruits because he is a steward, and not a ranger. Janos Slynt warns Thorne that since Jon is popular amongst the Night’s Watch, this will give him an edge over him when a new Lord Commander is elected. Slynt suggests sanctioning Jon’s expedition to Craster’s Keep so the mutineers may kill Jon, although Thorne merely walks off after Slynt’s suggestion. Later on, Thorne sanctions Jon’s mission to Craster’s Keep, but tells him that he can only take volunteers with him. However, after an impassioned speech by Jon, a number of black brothers volunteer to go and deal with the mutineers.
Jon survives the mission and returns to Castle Black unharmed, to Thorne and Slynt’s disappointment. When Thorne catches sight of Jon’s dire wolf, Ghost, he orders Jon to lock up his ‘wild beast’ or Ghost will become food for the Watch. Later at the meeting, Jon warns the Night’s Watch about the impending attack of Mance’s army and suggests the tunnel to be sealed to prevent giants from bringing it down and exposing the wall. However, Thorne rubbishes the claim and asks the First Builder, Othell Yarwyck, for his opinion. Yarwyck agrees with Thorne, though he has obviously been intimidated by Thorne’s tone of voice. He also sends Jon and Sam to keep a watch in the night to look out for Mance’s army.
When the wildling army arrives, Thorne watches from atop the Wall with Jon, noting “the biggest fire the North has ever seen” and the presence of giants and mammoths. He ruefully admits they should have sealed the tunnel as Jon advised. In a moment of compassion, Thorne goes on to explain the pressures and responsibilities of leadership to Jon, but promises him that if they fight as hard as they can, they will survive the night.
After ordering the first volley of arrow attacks against the main wildling army, Thorne is called to bring reinforcements below to Castle Black, where the smaller wildling force south of the Wall is attacking the lightly-defended fortress. Thorne leaves command atop the Wall to the inexperienced Slynt (who is promptly tricked into going below as well, leaving command on the Wall to Jon) and returns to the castle. As the wildling’s begin to breach Castle Black’s walls, Thorne gives an inspiring speech, promising that Castle Black and the Night’s Watch will still stand at daybreak, and rallies his men, personally leading the counter-charge. Thorne manages to kill several wildling’s before he confronts Tormund Giantsbane on the catwalks. They duel evenly for a time, but Tormund finally manages to wound Thorne, who escapes by rolling off the catwalk and falling onto a hay-bale below. The wounded Thorne is then carried to safety by two members of the Night’s Watch, while screaming at the remaining men fighting to hold the gate at any cost.
Alliser Thorne has recovered from the wounds he sustained during the Battle of Castle Black and continues to observe the new recruits. As Thorne walks through the courtyard, he gives Gilly a look of contempt due to his hatred of the wildling’s. Later, Thorne is present when Mance Rayder is executed by Stannis Baratheon for refusing to bend the knee.
With the choosing of a new official Lord Commander impending, Alliser seems to be the favourite to succeed Jeor Mormont due to his efforts during the Battle at Castle Black. Stannis Baratheon and Davos Seaworth attempt to use this to sway Jon to their side, implying that Alliser will make Jon’s life in the Watch miserable solely to undermine him. During the choosing, Alliser runs against Denys Mallister and Jon. While Thorne acknowledges Jon’s accomplishments, he also reminds the black brothers of Jon’s sympathy towards the wildling’s. However, Thorne loses by a single vote – that of Maester Aemon – and Jon is chosen as the new Lord Commander.
Stannis later advises Jon to send Alliser away to East watch by the Sea, but Jon prefers to keep him around in order to learn if he is plotting against him. At a meeting, Jon prepares to assign a black brother to oversee the digging of a new latrine pit. Alliser believes that Jon will use this as an opportunity to humiliate him, but is surprised and somewhat elated when Jon acknowledges his skills and names him First Ranger. When Janos Slynt subsequently defies Jon’s order of reassignment to Grey guard tower, Ser Alliser initially blocks the black brothers coming to seize Janos, but ultimately steps aside out of his newfound respect for Jon. He watches with the rest of the Watch as Janos is beheaded by Jon for refusing to follow orders.
As First Ranger, Thorne becomes a part of Jon’s inner council. When Jon proposes that they allow the remaining wildling’s to pass through the Wall in order to escape the coming White Walkers, Thorne is against the plan, reminding Jon that they have been enemies for thousands of years and caused the deaths of numerous sworn brothers.
Thorne is later present when Jon departs Castle Black with Tormund for Hard home to persuade the remaining wildling’s to surrender, denouncing the mission as reckless and an insult to all the black brothers who were killed by the wildling’s. He also quips to Sam that he is losing his friends, and by extension, his protection. It is possible that Thorne was in fact warning Sam about potential attacks on him and Gilly in his own, gruff way.
When Jon returns with the wildling’s he managed to rescue from Hard home, Thorne is visibly angered by the presence of wildling’s outside the Wall, but gives the order to let them inside after Jon shows himself. As the wildling’s are allowed through Castle Black, Thorne coldly quips to Jon that while he may have a good heart, it will get them all killed.
A while later, on Thorne’s orders, Olly lures Jon into the courtyard, where Thorne claims they have captured a wildling who may know where Benjen Stark is. Thorne, however, leads Jon to a post with a sign marked “Traitor” as a group of mutineers surround him, and he is the first to stab Jon and say “For the Watch”. Jon manages to push Thorne away, only for Othell Yarwyck, Bowen Marsh, two more officers and Olly to each take turns in stabbing Jon. He and the mutineers walk away and leave Jon for dead.
Thorne does not hide his role in the mutiny and manages to win over the majority of the Watch by reasoning that Jon was willing to risk the Watch’s future through his allegiance with the wildling’s. Effectively acting Lord Commander of the Night’s Watch once again, Thorne speaks with Davos Seaworth, who is guarding Jon’s body in a locked room with Dolorous Edd and other Black Brothers loyal to Jon, and offers him safe passage to the South with a horse and supplies, but Davos’s mocking request for mutton convinces Thorne that they have no intention of backing down, but will fight to the death. Thorne promises Davos that if he and Jon’s friends do not surrender, they will die.
Davos sends Edd to the wildling’s for help, and they breach the gate of Castle Black with the help of the giant Wun Weg Wun Dar Wun. Thorne attempts to rally the Night’s Watch to fight them off, but they are severely outnumbered and terrified of the giant, and the rest of Thorne’s brothers surrender. Only a handful resist, two of whom are killed. Thorne and the other brothers who helped in Jon Snow’s execution are subsequently taken as prisoners.
After Jon has been resurrected by Melisandre, he issues the mutineers’ execution. When Jon asks for his last words, Thorne disheartens Jon, stating that while he will rest, Jon will keep fighting. He expresses no regret for leading the mutiny, saying he prays he would have done the same thing over again even if he knew the outcome. Jon then proceeds to cut the rope to hang all of the mutineers, and orders Edd to burn their bodies.