Leo Costayne
Ser Leo Costayne, known as the Sea Lion, commanded the fleet of the Reach as Lord Admiral under the reign of Aegon III Targaryen. His name became tied to the last great naval campaign against the Ironborn, when the Crown sought to stop Dalton Greyjoy's raids on the western coast.
Chapter 2
Lady Johanna's promise
134 ACBooks only
Lord Alyn refused to carry the war to the Iron Islands themselves, but Lady Johanna Westerling, Lady of Casterly Rock, persuaded Ser Leo to try it on his own. His decision may have been swayed by Lady Johanna's promise to marry him if he delivered the islands to her young son.
In 134 AC Ser Leo sailed his forces to the Iron Islands. The disorder left by Dalton Greyjoy's death meant the Ironborn could not defend themselves in time: thousands died and dozens of villages and hundreds of ships burned.
The victory cost him nearly his whole fleet: three quarters of his ships were sunk or captured. Ser Leo Costayne was killed at Great Wyk by Arthur Goodbrother.