INTRODUCTION
“Your blood makes you a greenseer,” said Lord Brynden. “This will help awaken your gifts and wed you to the trees.” Three-Eyed Crow ( Lord Brynden), A Dance with Dragons – Bran III
What did Three-Eyed Crow mean when he claimed Brandon Stark’s blood made him a greenseer? “Blood” is typically referenced in relation to one’s lineage or ancestry. Hence, in this context, it can be postulated that “blood” insinuates to Brandon Stark’s lineage. But whose lineage? Brandon Stark is the son of Lord Eddard Stark and Lady Catelyn Tully two ancient and Nobel houses that trace their lineage all the way back to the First Men & Age of Heroes.
House Stark & Tully
House Stark, with its mysterious past and ties to Long Night, the Night’s Watch, the Children of the Forest, Direwolves and the Old God’s is the obvious strong contender. In addition, the fact that Brandon Stark can warg into his direwolf Summer & Hordor solidifies the argument further. Also, circumstantial evidence points to other House Stark members ability to warg into their direwolves. So is it House Stark? Before establishing the reasons for why Brandon Stark’s Stark lineage is not what Lord Brynden was referring to lets briefly turn to House Tully.
House Tully of Riverrun is one of the Great Houses of the Seven Kingdoms. An old noble house they trace their origins to the First Men and the Age of Heroes. The Tully’s rose to prominence during the Targaryen era and ruled over the Riverlands from their seat of Riverrun until the red wedding when House Tully’s lands, wealth and title are stripped and House Frey handed over the lordship of Riverlands. House Tully is related to Brandon Stark from his mother Catelyn Tully. Despite their long history which puts them in Westeros at the time of the Pact and the Long Night, they can be dismissed due to the absence of any historical evidence of links between House Tully & Greenseers.
That leaves us with House Stark. Was Lord Bryden referring to Bran’s stark lineage? Two issues throw that theory into question? One is the absence of any historical evidence of House Stark members having the gift of greensight. A possibility exists but no evidence has been presented thus far.
The second and most important issue is Lord Bryden’s emphasis on lineage as an important variable in becoming a greenseer. If this is, in fact, true then Brandon Stark & Lord Bryden must share a common lineage. But one is a Stark and the other a bastard Targaryen.
Hence, what connects Brandon Stark and Lord Bryden Blackfyre? It is HOUSE BLACKWOOD.

HOUSE BLACKWOOD OF RAVENTREE HALL
House Blackwood of Raventree Hall is a Nobel house from Raventree Hall in the Riverlands. They blazon their arms with a flock of ravens on scarlet surrounding a dead weirwood upon a black escutcheon. Raventree is located in Blackwood, north of Riverrun and the Red Fork.
Although enmeshed in Riverlands history and famous for its rivalry with its neighbour House Bracken, House Blackwood is not from Riverlands but from the North of Neck, the runic translations by Maester Barneby support their claim.

Further, House Blackwood members also claim they ruled over most of Wolfswood until they were excommunicated from the North by House Starks, the Kings of Winter. No additional information exists about this historical event. However, the two revelations make them an important outlier in the war for Northern dominion waged between House Starks & the petty kings that ruled over the North during the Dawn Age.
House Starks conquest and dominion over North was both bloody and long. In the end, they established their rule over the North by either defeating the petty kings and feudal lords who ruled before their arrival or extinguished the houses that refused to legitimise their rule even after being defeated. ( It is acknowledged that not a lot of historical evidence exists about their conquests.)
House Blackwood is the only house which neither accepted the rule of the Kings of Winter or was exterminated from history. It can be argued that the Free Folks existence beyond the wall is another example. However, the Free folks do not claim to be have ruled the North and importantly throughout history were in constant conflict with House Stark, making them distinct from House Blackwood.
In addition, there is an important piece of information about House Blackwood on the eve of Aegon Targaryen’s conquest of Westeros that is of importance.
House Blackwood & Gift of Prophecy
On the eve of Aegon Targaryen’s conquest of Westeros, the Riverlands was ruled by the Harren the Black of House Hoare, King of the Isles and the Rivers who ruled from Harrenhal, the gigantic castle next to God’s Eye. Harren’s ironborn forebearers had thrown down the last of the river kings centuries earlier. The River Kings last stand against the invading forces of Iron Islanders & House Hoare came in the form of Lady Agnes of House Blackwood. However, her military expedition was cut short when members of House Bracken attacked her men. Lady Agnes and her sons were captured and delivered to King Harwyn Hoare, where she had to watch her sons put to death in front of their mother.
Yet Lady Agnes did not weep if the tales are true. “I have other sons,” she told the King of the Iron Isles. “Raventree shall endure long after you and yours are cast down and destroyed.Your line shall end in blood and fire.”
– A World of Ice & Fire

The blood and fire as predicted by Lady Agnes came in the form of Aegon Targaryen’s conquest of Westeros two centuries later. Balerion the Dread, the dragon of Aegon the Conqueror, attacked & burned down Harrenhal, killing the last of the House Hoare members within its castle.
HOUSE BLACKWOOD, STARK & TARGARYEN
∗ Cregan Stark married Alysanne Blackwood
∗Aegon Targaryen IV mistress Melisa Blackwood
∗ Aegon Targaryen V married Betha Blackwood
∗ William Stark married Melantha Blackwood
Aegon IV and Melisa Blackwood had a son named Brendyn Rivers, who was a legitimised Great Bastard who went by the name Lord Bloodraven. As a Targaryen loyalist, he broke the tradition of guest right and was sent to the Wall to serve his prison sentence.
In the North, serving the Night’s Watch, he rose to become the Lord Commander and soon after disappeared beyond the wall, only to reappear decades later, to Brandon Stark as the Three-Eyed Crow, a powerful and the last of the greenseers of the Children of the Forest.
On the other hand, Melantha Blackwood is the great-grandmother of both Lyanna and Eddard Stark. Brandon Stark, the chosen replacement of the current greenseer is the son of Eddard Stark & Catelyn Tully.
On the other hand, both Blackwood sisters are great grandmothers of Rhaegar Targaryen and Lyanna Stark respectively. In turn both the sisters and the great-great-grandmothers of Jon Snow, the son of Rhaegar Targaryen & Lyanna Stark.

Greenseers & House Blackwood
As we already know, both Brynden Blackfyre & Brandon Stark have the gift of greensight. Bryden is the current Three-Eyed Crow while Brandon is in training. The blood or lineage could be exclusively Stark or Targaryen. Daneys Targaryen’s dream or prophecy was prophetic enough for her father to leave the Freehold of Valyria . However, what stands out is the fact, is that House Starks did not have any known history of members who claimed any abilities of foresight. Yet Brandon Stark is picked as the next greenseers, with Brynden Blackfyre claiming the link to blood and green sight ability. The only link between them is House Blackwood. In addition, both these greenseers come into picture only after the House Blackwood married into House Stark & House Targaryen.
CONCLUSION
In conclusion, was Lord Brynden, the Three-Eyed Crow referring to House Blackwood who are related to both Starks & Targaryens? Without additional information, no definitive conclusion can be reached. However, there is enough evidence to suggest that at the very least House Blackwood of Raventree Hall is more important to the history of Westeros , than they appear to be in the “A Song of Ice & Fire” series.
Their importance stems from House Blackwood’s claim of Northern lineage & rule of wolfswood, the area surrounding Winterfell, substantiated by runic evidence, and their gift of prophecy. Importantly, in addition to the above factors, House Blackwood is the common denominator that linked House Starks & Targaryen.
