House Costayne

House Costayne is a noble house in the Reach sworn to House Hightower. Their seat, Three Towers, is situated where the Whispering Sound meets the Redwyne Straits. One of the principal vassals of the ancient Hightower kings, the Costaynes have vigilantly watched the waters leading into Oldtown throughout history.

Three Towers
Three Towers, inconsistently referred to as the Three Towers, is the ancient seat of House Costayne. It sits at the edge of a cliff along the shore of the Whispering Sound, more or less where it meets the Redwyne Straits. Its three eponymous towers are each topped with a beacon, and a small harbor lies on the shore below, housing its fleet of ten warships. It is surrounded by fertile land, and though its agricultural output is typical of its region, the overpopulated city of Oldtown relies greatly on the Costaynes' grains.

History
The exact origins of House Costayne remain unclear, but they have held their seat since ancient times. Historians generally believe that they were empowered by the Hightower kings of old, charged with watching the Whispering Sound to alert their liege of approaching enemy ships. Though they have always been a relatively minor house by the standards of the Reach, the members of House Costayne have still made their mark on the history of Westeros at large. "Long Tom" Costayne served the Kingsguard for sixty years, possibly the longest tenure of any knight who donned the white cloak.

Elinor Costayne was one Maegor the Cruel's three "Black Brides", wed to him in a single ceremony during the final year of his reign. Centuries later, Aemon Costayne achieved renown as a singer and performed at the wedding of Joffrey Baratheon and Margaery Tyrell.

The Costaynes have been among the first to declare their allegiance to doomed causes several times throughout history. During the Dance of the Dragons, they aligned themselves with Rhaenyra Targaryen, standing against the Hightowers, who sided with Aegon. At the Battle of the Honeywine, Lord Owen Costayne was slain by the Valyrian sword of Jon Roxton. Likewise, House Costayne sided with the Blackfyres during the Blackfyre Rebellion. Despite the failure of this cause, the Costaynes took part in the conspiracy that intended to incite a Second Blackfyre Rebellion.

In the present century, the Costaynes followed the example of their liege by opposing Visaera Targaryen during the Mummer's War. More recently, Lord Kevan Costayne zealously supported the Warsmiths in the Second Hammer Uprising. His sole son and heir, Jory, was slain in a skirmish, and at the war's conclusion, Lord Kevan was sentenced to spend the rest of his years on The Wall.

Recent Events
With Lord Costayne deposed and his only son deceased without issue, his eldest daughter Arianne Greyjoy was recalled from Pyke and installed a Lady of Three Towers. She reverted her surname to Costayne, and did the same for her two children, Alannys and Axel. Arianne returned to the Reach with fifteen years of experience as an unofficial steward for House Greyjoy, in whose service she supervised a number of construction projects. She immediately set out to utilize such talents to renovate Three Towers and improve the economic condition of her lands, which had been largely neglected by her predecessor.