House Vance is an ancient Riverlands house that stands divided between two branches, each tracing its line to the same ancestral stem. The elder branch, seated at Atranta, bears quartered arms of a green dragon on white and a white tower on black; the younger branch, lords of Wayfarer's Rest, quarter a black dragon on white with two golden eyes in a golden ring upon black. Both branches are sworn to House Tully of Riverrun and have answered Riverrun's call through rebellion and war alike. The house is old enough that no certain founding is recorded, and whether they are of First Men or Andal descent is a question their own maesters cannot settle.
By the time of A Game of Thrones the Vances are split in lordship but not in allegiance. Lord Norbert Vance holds Atranta and Lord Karyl Vance keeps Wayfarer's Rest, two cousins ruling two seats within the same region. When Riverrun summons its bannermen both lords ride, bringing the swords and spears of the Vance lands to the Tully muster, a divided house that nonetheless presents a united front beneath the rippling blue and red of their overlord's banner.