 The first ruler to unite the Riverlands was Benedict Justman, but the Justman dynasty died out three centuries later.The Durrandons conquered the Riverlands, but lost rule of it to Harwyn "Hardhand" Hoare, King of the Iron Islands.At the time of Aegon's conquest, the Riverlands were ruled by Harwyn's grandson, Harren the Black, king of the Iron Islands, and the Tullys were local nobles who rebelled against him by joining Aegon the Conqueror.