House Costayne

House Costayne of the Three Towers is a vassal house that holds fealty to House Hightower of the Hightower. Their castle is the Three Towers.

History
Lady Elinor Costayne was a wife of King Maegor Targaryen, who married her for her proven fertility after his first three wives failed to give him an heir, killing her husband in order to obtain the marriage. However, she miscarried just like previous wives.

In the books
In the A Song of Ice and Fire novels, Lady Elinor Costayne was married to Ser Theo Bolling and was forced to marry King Maegor Targaryen after he killed her husband.

During the Dance of the Dragons, Lord Owen Costayne declared for Princess Rhaenyra Targaryen, despite his liege lords in House Hightower declaring for Rhaenyra's brother. He was killed in the Battle of the Honeywine by Ser Jon Roxton with his Valyrian steel sword Orphan-Maker. His successor accompanied the lords of House Beesbury and House Redwyne accompanied the High Septon to the coronation and wedding of King Aegon III Targaryen to his second wife, Lady Daenaera Velaryon. A girl of House Costayne was among the names suggested by Samantha Tarly as possible brides for the king.

Ser Leo Costayne invaded the Iron Islands following the death of Lord Dalton Greyjoy, but he was killed at Great Wyk.

House Costayne fought on the side of House Blackfyre in the Blackfyre Rebellion. In the Battle of the Redgrass Field, the Costayne force fought on the left of Daemon I Blackfyre's host. A son of the lord participated in Lord Ambrose Butterwell's wedding festivities. The lord married to the daughter of Lord Ambrose by his first wife. He was later defeated by Ser Glendon Flowers in a tourney at Whitewalls. Once the second Blackfyre Rebellion was put down, a servant of House Vyrwel claimed to be a spy for Brynden Rivers and was killed by a man in service to House Costayne.

Long Tom Costayne was a member of the Kingsguard for sixty years.

Aemon Costayne was among the seven singers selected to sing at the wedding of King Joffrey Baratheon and Lady Margaery Tyrell

Known members

 * Unnamed Lord Costayne, ruling during the reign of King Maegor I Targaryen.
 * Lady Elinor Costayne, his daughter, married to Ser Theo Bolling, giving him three sons, then married to King Maegor I.
 * Son(s)
 * Lord Owen Costayne, Lord of the Three Towers during the Dance of the Dragons.
 * Ser Leo Costayne, lord admiral of the Reach during the reign of Aegon III Targaryen.
 * Ser Tom Costayne, known as Long Tom for serving in Kingsguard for sixty years.
 * Unnamed Lord Costayne, fought for Daemon I Blackfyre during the First Blackfyre Rebellion.
 * Unnamed Lord Costayne, his son. He married a daughter of Lord Ambrose Butterwell.
 * Ser Tommen Costayne, who participated in the tourney at Ashford Meadow in 209 AC.
 * Lord Tommen Costayne, Lord of the Three Towers.
 * Aemon Costayne, a famous singer.

House Costayne is a reference by George R. R. Martin to the author. The family's sigil references two of Costain's novels, ' and '.