A moratorium is in effect on adding information from Fire and Blood until December 20th.
King of the Isles and the Rivers
Harwyn Hoare, King of the Iron Islands, conquered the Trident from the Storm King Arrec Durrandon. Harwyn and his successors, Halleck Hoare and Harren Hoare, spent most of their reigns in the riverlands fighting against neighboring kingdoms rather than ruling from the Iron Islands. It is said of Harwyn that "His palace was a tent, his throne a saddle." Halleck ruled from a tower house at Fairmarket, while Harren the Black constructed the massive castle of Harrenhal along the Gods Eye.
The Hoare line was extinguished by Aegon the Conqueror during the War of Conquest, ending the usage of the title. The Iron Islands then passed to House Greyjoy of Pyke and the riverlands passed to House Tully of Riverrun.