During a fierce winter's storm, he came to Tyrsis to speak to King Ruhl Buckhannah and prince Balinor Buckhannah. He warned them that after 500 years the Warlock Lord Brona returned to Skull Mountain and once more menaced the peace of the Four Lands. The King's advisor Stenmin spoke against him, accusing him for being a troublemaker and a liar who sowed dissension for his own ends. Thus Allanon's warning went unheeded in the kingdom. It was Balinor who believed his words and spoke in his favor. He agreed to aid his quest and together left Callahorn. He then sought the last descendant of Jerle Shannara to wield the only weapon which could destroy Brona, the Sword of Shannara.
He united the heroes of the Third War of the Races to defeat Brona. From Culhaven he was sent with Balinor Buckhannah, Hendel, Shea Ohmsford, Menion Leah and 2 Elves on the quest to find the Sword of Shannara. He led Shea and Balinor through the deadly Hall of Kings on their way to the Druid's Keep.
20 years after the defeat of the Warlock Lord, Allanon came to Shady Vale to protect it from monsters. He came right on time to save Jak Ohmsford, from a monster. He ordered Jak to go to Leah and warn Menion Leah of an oncoming peril, and stays with Shea Ohmsford in the Vale to defend the village.
Allanon is later seen in Leah, after Menion was cured of a poison. There he explains that the Warlock Lord has returned from the dead and tasks Jak with traveling to Tyrsis to warn King Balinor Buckhannah and to claim the Sword of Shannara like his father. Allanon then leaves for the Valley of Shale to speak with the shade of Bremen.
He then came to Tyrsis at the time when Jak lifted the curse and released the Sword from its Vault. Then they saw that the Sword was broken. Allanon sent Jak to gather items: Elfstones, the Hammer of Power, the Magic Torc and the Black Irix, and bring them to Hadeshorn where Bremen would use them to reforge the sword. He then left for Hadeshorn to try to prevent Brona from gaining more power.
He waited for Jak and his companions in the Valley of Shale and performed the ceremony to reforge the Sword of Shannara. He then led the team to the Hall of the Kings and he remained behind to keep monsters back allowing them to enter. As Jak banished the Ildatch, Allanon found Telsek and the two reunited with Brendel. All together went to get Jak, whom they found unconscious.
They reunited back in Tyrsis in the ceremony to seal the Sword of Shannara back in its vault. Jak surrendered to him Stenmin's grimoire.