- "Might be useful. Ch'Vyalthan's a dreadful writer but an excellent researcher."
- ―Ebrose to Samwell Tarly
Ch'Vyalthan was an Archmaester of the Citadel and the author of the books An History of the Great Sieges of Westeros and All History of the House of Lannister.
Biography
Season 2
Tyrion Lannister refers to his book An History of the Great Sieges of Westeros when preparing the defense of King's Landing. Varys criticizes him as an uninspired writer. Tyrion and Bronn debate how to correctly pronounce his name, but Varys offhandedly reveals the proper form: "sh(uh)-VY-al-thun".[1]
Season 7
Archmaester Ebrose hands his book All History of the House of Lannister to Samwell Tarly, claiming that it might be useful when writing A Chronicle of the Wars Following the Death of King Robert I.[2]
In the books
No mention of an Archmaester Ch'Vyalthan is made in the A Song of Ice and Fire novels.