Murtaugh Allsbrook was Ren Allsbrook's grandfather and a member of House Allsbrook by marriage. He and his grandson were members of the rebel group working to restore Aelin Galathynius to the throne of Terrasen.
During the conquest of Terrasen, Murtaugh and his grandson Ren escaped the butchering of Terrasen's noble families thanks to a distraction caused by Ren's parents. They were subsequently killed, and Murtaugh managed to evade Adarlan's reach for the next ten years, becoming part of the rebel movement against its rule.
Murtaugh first appears during a meeting between him, Ren, and Aedion Ashryver. They offer their help to Aedion and Aelin's court but are bluntly told by Aedion that they have nothing to offer. He refuses to tell them where Aelin is, bringing up the fact that Nehemia Ytger died while on their watch. Ren tries to argue but Murtaugh stops him, saying it might be better they don't know. Ren demands to know what they should tell the court then. Murtaugh reveals that Ravi and Sol of Suria are still alive, and mentions that Ravi might be willing to fight for Terrasen. They discuss other people loyal to Terrasen who escaped and might be able to fight. Aedion is dismayed at the lack of allies they have, and Murtaugh counsels him that not everyone will be eager to accept Aelin as queen because of her ten year absence.
Aedion arranges a meeting with Chaol Westfall for the three of them. However, Ren and Murtaugh are followed and attacked before they arrive. Ren kills many of their attackers and Murtaugh retreats somewhere safe while Ren continues on to the meeting. Murtaugh appears twenty minutes later, agitated by the attack and worried about his grandson, who has sustained injuries.
While Ren recovers, Murtaugh tells the story of their escape from Terrasen and research into the disappearance of magic in Erilea. Aedion asks where Ren can be moved; Murtaugh reveals that they have no home. Chaol offers them the use of Aelin's apartment. Murtaugh continues trying to pinpoint the source of the spell that blocked magic. He spends a few weeks in Skull's Bay, ignoring Ren's offer of help, and returns to Rifthold after his trip with bad news; General Narrok was sighted in Skull's Bay but was pushed out by Rolfe, who now reports strange noises from the islands and claims to have seen a monstrous creature with a black collar. Narrok has gone to Wendlyn, and now the rebels know that the king has more powerful tricks up his sleeve than initially thought.
A message arrives from Sol of Suria inviting Ren to visit him. On the day of his departure, Murtaugh arrives breathless at the apartment and tells them that the queen is alive, that Aelin Galathynius is in Wendlyn and is reported to have killed Narrok and the forces he took there with fire magic. Overcome with excitement at the news, Murtaugh tells Ren to stay in Rifthold while he spreads the news of the queen's return. He rides off to carry the message, leaving Ren with orders to find him once he's gathered enough information.
Murtaugh, Ren, and Darrow meet with Aelin, Rowan Whitethorn, Aedion, Lysandra, and Evangeline in a small town in Terrasen to discuss legal matters regarding Terrasen's royal throne. Murtaugh is considerate of Aelin, coming into the meeting with open eyes and giving Aelin a chance to prove her worth. He is understanding of her position and wishes for her to be Queen of Terrasen. Aelin leaves Evangeline, Lysandra's ward, in the care of Murtaugh and Ren while the rest embark on their journey across Erilea. Murtaugh promises to protect Evangeline and keep her safe.
Murtaugh helps organize the armies and battle in the north along with Ren, Darrow, and Aedion. During the Battle of Orynth, Murtaugh leaves the relative safety of the castle to handle the western wall and the siege tower. Later, it is revealed that Murtaugh fell during the battle, cut down by Valg foot soldiers as he fought to defend Orynth. Murtaugh is laid in a small chamber in the Great Hall of Orynth's castle as Ren, Aedion, and Lysandra mourn for his loss. Murtaugh is remembered as a brave, noble, and good man, as described by Lysandra.
Fiercely loyal to Terrasen, Murtaugh risked life and limb to restore Aelin Galathynius to Terrasen's throne by working with the rebels in Rifthold. Unlike his grandson, however, Murtaugh was relatively calm and seemed to prefer peace to violence. However, he was brave and still fought for Terrasen despite his old age.
Murtaugh was a thin, elderly man. He was described as looking slow, old, and frail, but kept his chin high and back straight as he walked into battle.
- Heir of Fire (first appearance)
- Queen of Shadows (mentioned only)
- Empire of Storms
- Kingdom of Ash