Aneirin was a city elf from the Alienage of Denerim in Ferelden. He was sent to the Circle of Magi like all mages are and put under the apprenticeship of Wynne. Coming from the Alienage he was naturally mistrusting of humans but Wynne believed he was just being stubborn and was rough on him. He tried to communicate with Wynne but after being berated over a trivial matter he tried to escape the tower in an attempt to find and join the Dalish.
The Templar’s labeled him a ‘Blood Mage’ and ‘Abomination’ even though he was just fourteen at the time was neither of those things. They tracked him down using his phylactery and ran him through, leaving Aneirin for dead. Despite Wynne’s inquiries the Templar’s refused to tell her whether Aneirin suffered, leaving Wynne to regret his death all her life.
The Dalish found Aneirin and saved him. He continued to live with the Dalish, spending most of his time away from their camp and alone in the forest with the wildlife until he was found by Wynne and the Warden. Wynne is overjoyed to see him and apologizes but Aneirin insists that despite what she may think he learned a lot from her. Wynne asks him to return to the Circle of Magi to which Aneirin says he’ll consider.