Lord Owen Costayne was the head of House Costayne and Lord of Three Towers during the Dance of the Dragons.


Lord Owne declared himself for Queen Rhaenyra Targaryen, against the will of his liege lord, Ormund Hightower, who declared for King Aegon II Targaryen. Lord Owen then fought in the Battle on the Honeywine, riding with Lord Alan Tarly and Ser Alan Beesbury in cutting off the retreat of the forces of House Hightower.

The enemy started to crumble initially, but the arrival of Prince Daeron Targaryen on his dragon Tessarion changed the course of the battle. Other leaders were taken prisoner after the battle, but Owen was defeated and mortally wounded by Ser Jon Roxton, who wielded Orphan-Maker, and eventually died of his wounds, although it was a slow death.