Brynden Rivers came into the world in 175 AC, one of the four bastards Aegon IV legitimized on his deathbed and so one of the four "Great Bastards" whose grievances would bleed the realm for a century. His mother was Melissa Blackwood, sixth of the king's mistresses, and the pale skin and blood-red birthmark under his left eye — a stain the smallfolk read as a dragon, or a raven, or the king's own guilt made flesh — gave him a name before he ever earned one. He earned the rest of it soon enough.
He fought for the crown, not for his half-brother Daemon Blackfyre's rebel one. At Redgrass Field in 196 AC, by every surviving account, it was Brynden's bow that ended the First Blackfyre Rebellion: three black arrows, one after another, took Daemon and both the sons riding beside him. Whether that was soldiership or something closer to a curse is a question the chronicles leave open, and Brynden himself was not a man given to correcting rumor that served him.
He rose after that the way careful, watched men rise — Hand to Aerys I, Hand again to Maekar I, a name attached to every faction's fear of sorcery and to no faction's certain loyalty. When Maekar died in 233 AC, Brynden called the Great Council that should have settled the Blackfyre question peacefully; instead a rival claimant died under his safe conduct, on his watch, in circumstances the record does not care to clarify. The new king's first act was to arrest his own Hand for the killing.
The Watch, in the end, was where the realm's inconvenient men went, and Brynden went there rather than to the block. He commanded it from 239 AC and, in 252 AC, rode north of the Wall and did not ride back. Only his rumored fate is on record now: a thing grown into a weirwood at the edge of memory, greenseeing across centuries, first glimpsed — if the account can be trusted at all — by a crippled Stark boy who came looking for a crow with three eyes.