The Fires of the Freehold
The Fires of the Freehold is written by Galendro and contains the history of the Valyrian Freehold. No complete copy is known to exist in Westeros. The Citadel of Oldtown's copy lacks twenty-seven scrolls. Despite this, Galendro's work is widely considered to be the most definitive history on the Freehold.
In The Fires of the Freehold it is written that when Valyria came to the aid of her most distant daughter, a hundred dragons took to the skies, descending on Qarlon the Great and his army, who had laid siege to Norvos.