Winged Knight

The Winged Knight was a legendary figure of the Age of Heroes.

Biography
According to legend, the Winged Knight flew atop a giant falcon, landing on the Giant's Lance in the Vale during the Andal Invasion, and slaying the Griffin King, the last of the First Men Mountain Kings. He then became the ruler of the Vale.

In the books
In the A Song of Ice and Fire novels, the Winged Knight is a legendary figure who is often conflated with the Andal knight Artys Arryn, who defeated the First Men at the Battle of the Seven Stars and founded House Arryn. Singers and storytellers present him as a knight, knighthood being an Andal tradition. He is also said to have commanded armies of eagles and held a good relationship with giants and merlings. His wife was one of the Children of the Forest, and died giving birth to a son. Maester Yandel believes that singers intentionally conflated the Winged Knight with Ser Artys in order to curry favor with the latter's descendants. This would have given rise to the stories of Artys claiming the Eyrie, even though it was only constructed by his descendants.

Robert Arryn (Robin Arryn in the show) has a fondness for tales about the Winged Knight, and Sansa Stark comes up with the idea of making him comfortable by establishing a bodyguard of Winged Knights. Petyr Baelish likes the idea and sets about forming the Brotherhood of Winged Knights, with its first eight members being the winners of the upcoming tournament at the Gates of the Moon.

In the Season 1 Complete Guide to Westeros, Ser Artys' story is also conflated with that of the Winged Knight by Catelyn Stark, although it is not acknowledged that they are not the same person. In the Season 6 Histories and Lore however, Lord Baelish recounts the true story of Ser Artys, with no reference to the Winged Knight, thus establishing the difference between the two.