House Connington of Griffin's Roost is an old stormlander house holding a high promontory on the coast of Cape Wrath, sworn since the Conquest to Storm's End. Their two combatant griffins, red on white and white on red, are reckoned among the elder devices of the Stormlands, and the roost itself, perched on a sea-cliff above the Cape, has been a strong-place since the days when griffins were a thing as common in Westeros as eagles.
In the living memory of the realm the house is bound up with the fate of one man, Jon Connington, who as a boy was companion and friend to Prince Rhaegar Targaryen and as a young lord rose to be Hand of the King to Aerys II. After the rout at the Battle of the Bells he was stripped of his titles, his lands, and his lordship, and word went out that he had drunk himself to death in exile in the Free Cities. King Robert gave Griffin's Roost to Jon's cousin Ronald Connington and the diminished style "Knight of Griffin's Roost," lest a Connington again be reckoned a lord of the realm.
By the events of A Dance with Dragons Jon Connington is anything but dead. He has crossed back into Westeros at the head of the Golden Company in the train of a young man calling himself Aegon, sixth of his name, said to be the trueborn son of Rhaegar and Elia of Dorne. Griffin's Roost has been retaken from Ronald's son Ser Ronnet, called Red Ronnet, and the griffin banner flies above the cliff once more for a king whose claim the rest of the realm has not yet heard.