Luwin was the Maester of Winterfell and a loyal servant to House Stark. He acted as a surrogate parent to Bran Stark and Rickon Stark in the absence of their family.
Luwin is a Maester, a learned man of science and medicine, and serves House Stark of Winterfell. House Stark are Lords Paramount of the North. The North is one of the constituent regions of the Seven Kingdoms and House Stark is one of the Great Houses of the realm. Luwin is very loyal to the Starks and they value his wise counsel and experience. He delivered all five of Lady Catelyn’s children. He serves as a tutor to the male children.
Luwin organises the preparations for a royal visit with Catelyn Stark. Catelyn spots Bran climbing Winterfell’s walls and scolds her son in front of Luwin. Luwin stands behind the Starks as King Robert arrives. The next night Luwin delivers a letter from Lysa Arryn to Catelyn and Eddard Stark. He discusses its content with them and counsels that given Lysa’s claims that the Lannister skilled Jon Arryn it is important that Eddard take up Robert’s offer to make him Hand of the King. Bran is injured in what seems to have been a climbing accident.
Luwin tends to Bran’s injuries and predicts that he will survive. Eddard goes to King’s Landing to serve as hand and takes many of his retainers with him. Luwin goes to Catelyn to discuss finances and appointing replacements. Catelyn is distraught over Bran’s condition and refuses to participate. Robb Stark agrees to work with Luwin instead. An assassin attempts to kill Bran but is foiled by Bran’s dire wolf Summer. Luwin meets with Catelyn, Robb, Theon Greyjoy, and Rodrik Cassel in the Gods Wood of Winterfell to discuss the circumstances of Bran’s injury. Catelyn reveals that she found a blond hair inside the tower where he was found.
Luwin cautions restraint and Catelyn plans to go south personally to deliver the news to Eddard. Bran awakens after she leaves but is paralysed from the waist down. Luwin meets with Tyrion Lannister in the main hall of Winterfell alongside Robb. They offer a cool reception until Tyrion provides plans for a saddle that would allow Bran to ride. Luwin tutors Bran on the regions and families in the Seven Kingdoms and notes that amongst House Greyjoy’s noted skills is a tendency towards failed rebellions. Bran is upset at the continued absence of his parents and sullenly tries to provoke Luwin.
Luwin warns off Theon Greyjoy from Osha, a wildling prisoner captured near the castle. He then questions Osha himself. She claims that the White Walkers are on the move. He dismisses this as a fable, but Osha tells him that the Walkers were not wiped out thousands of years ago, but have merely been asleep. She claims that they are not asleep any more.
Eddard is arrested for treason after the death of Robert. A letter from Sansa reaches Winterfell, pleading with a disbelieving Robb to bend the knee to Joffrey Baratheon. Maester Luwin correctly identifies the letter as the work of Queen Cersei. Robb refuses to consider the request and sends out ravens, summoning Eddard’s lords banner men to assemble their armies at Winterfell. Robb marches south leaving Luwin to care for Bran. Eddard is executed for treason on King Joffrey’s orders. Luwin tells Bran and Rickon the news of Eddard’s death.
As Maester at Winterfell, he becomes ever more of a father-figure to Bran and Rickon with their father dead and their mother away. He provides council to Bran as he acts as Lord of Winterfell. Bran questions Luwin about his strange dreams and Luwin reveals to him the valyrian steel link in his Maester chain, the sign that he studied the “higher mysteries” – magic – and asserts that if magic ever existed it has left their world long ago (unaware of Daenerys Targaryen’s dragons in the east).
Theon Greyjoy, who was last seen riding off with Robb, later returns to Winterfell with a crew of fellow iron born. They lure the garrison of Winterfell away by feinting at Torrhen’s Square and then seize the poorly defended castle. Luwin is able to send word to King Robb Stark before being captured. Theon assembles Luwin and the rest of Winterfell’s inhabitant in the courtyard where he has Bran publicly surrender the castle to him. He then turns to Luwin and orders him to send ravens to his father and sister, informing them of his victory.
Upon noticing Luwin’s icy stare, Theon asks Luwin if he remembers his oath to serve the Lord of Winterfell, no matter their family name. Luwin grudgingly replies he does, and Theon reminds him that he is now the Lord of Winterfell and repeats his order. Luwin walks off to do as he is told but then Ser Rodrik Cassel, Winterfell’s castellan and master-at-arms, is forcefully brought forward to Theon by Lorren and another iron born. When Theon sentences Ser Rodrik to death after the latter openly spits in his face, Luwin tries to convince Theon not to make a hasty decision and that Ser Rodrik is worth more to him alive than dead. Theon briefly considers Luwin’s advice but ultimately dismisses him, due to Dagmer’s influence, threatening to have him executed as well if he doesn’t back down. Theon then proceeds to execute Ser Rodrik to the horror of Bran, Luwin, and the rest of Winterfell’s inhabitants.
When Osha frees the boys and flees the castle, Theon has Luwin accompany him as he attempts to hunt the escapees down. Luwin begs him to spare them. They lose their scent at a nearby farm. Theon has Luwin sent home and then later returns to Winterfell with the burned corpses of two children, publicly claiming that they are Bran and Rickon. The citizens of Winterfell scream and sob at the sight, but Luwin’s scream of anguish is the loudest and most painful to hear.
A few days later, Luwin spots Osha sneaking into the catacombs. He realises that the corpses must be Jack and Billy, the two orphans whom Bran had assigned to assist a kindly shepherd, and follows her to confirm his suspicion. She tells him they doubled back through a stream to mask their scent. Luwin urges her to keep the truth of Theon’s actions from the boys, saying Bran specifically would blame himself. Unbeknownst to Luwin, however, Bran overhears everything.
Winterfell is later surrounded by Northmen under the command of Ramsay Snow, Lord Roose Bolton’s bastard son, who infuriates Theon by blowing a horn all through the night. Despite acknowledging how kind his captors were to him, Theon tearfully vents his anguish over being constantly reminded by everyone, including Luwin, how lucky he was to be a prisoner of the Starks. Assuming a much more sympathetic tone, Luwin advises Theon to flee to the Wall and join the Night’s Watch so that he might save his life and redeem himself, adding he knows Theon is not the ruthless man he is pretending to be. Theon owes to Luwin that he has done terrible things but refuses to deviate from the course he has set, saying that is too late and he has gone too far to ever pretend to be anyone else, and also fearing that Jon Snow will most likely kill him for his actions. He tries to rally his men for battle, not knowing they plan to hand him over to the Northmen in exchange for their own lives. When Theon concludes his speech to his fellow Iron born, they immediately initiate their plan and knock him out. Despite Theon’s betrayal, Luwin is visibly mortified when he sees what the Iron born are doing and tries to intervene but ends up fatally stabbed by Dagmer, who then has Theon dragged away.
Despite his injury, Luwin escapes from Winterfell before she is sacked by Ramsay and makes his way to the gods wood, where he lies bleeding by the pool. Near death, he is found by Bran, Rickon, Osha and Hodor. He insists that the boys go north to the Wall as there are too many enemies in the south. He tells them that Jon will be able to keep them safe and tell their mother of their survival. Luwin affirms his pride at having served the Starks, particularly in raising their children. He sends them away and asks Osha to give him a quick death; having grown to greatly respect the Starks and their fellows, Osha does so.
Following House Bolton’s extinction after the Battle of the Bastards, Maester Wolkan is appointed to serve as House Stark’s new maester to replace Luwin. While discussing food rations for the North, Wolkan promises to refer to Luwin’s old notes for information regarding the century’s longest winter, as Luwin kept records of every raven scroll.
When Arya Stark returns to Winterfell, she asks for Luwin and Rodrik Cassel to prove her identity to two disbelieving guards, but is informed that the maester at Winterfell is now Wolkan, meaning that Luwin cannot prove her identity.