House Seaworth of Cape Wrath was born in 284 AC, when Davos, a common smuggler, broke the Redwyne cordon to bring foodstuffs to the starving garrison of Storm's End during Robert's Rebellion. Lord Stannis Baratheon knighted him for it and granted him a small keep and hunting wood on Cape Wrath, though Davos paid for his years of smuggling with the last joints of four fingers on his left hand. Though their keep lies in the stormlands, House Seaworth is sworn not to Storm's End but to House Baratheon of Dragonstone, and bears a black ship charged with an onion upon its sail, on pale grey.
Ser Davos remained one of Stannis's most loyal men through the War of the Five Kings, touring the stormlands to rally the storm lords, sending his ships to carry word of Stannis's claim as far as White Harbor and the Free Cities, and rowing Melisandre into Storm's End under parley. Four of his seven sons, Dale, Allard, Matthos, and Maric, died alongside him at the Battle of the Blackwater.
Rescued from the wreck of Blackwater Bay, Davos was nearly imprisoned for plotting against Melisandre before Stannis named him Hand of the King, Lord of the Rainwood, and Admiral of the Narrow Sea after Alester Florent's betrayal. Reported executed by Lord Wyman Manderly in White Harbor, Davos in truth survived, a condemned look-alike dying in his place, and was sent north to find Rickon Stark, while his son and heir Devan remained at Castle Black with Melisandre when Stannis marched on Deepwood Motte.