The Red Dragon and the Black
From A Wiki of Ice and Fire
The Red Dragon and the Black is a book written by Grand Maester Merion. The book remains unfinished, possibly due to Merion's death in 259 AC.
The book describes, possibly amongst other things, the events leading up to the First Blackfyre Rebellion. It is Merion's work that suggests that Brynden Rivers was involved in King Daeron II Targaryen learning that Daemon Blackfyre meant to declare himself king within a moon's turn.