Leo Costayne

In 133 AC the Crown sent Lord Alyn Velaryon to the Westerlands to deal with Dalton Greyjoy and his raids. Twenty House Hightower warships under Ser Leo Costayne joined the Velaryon fleet for the campaign.

Before that fleet reached its destination, Dalton Greyjoy was killed and his men returned to the Iron Islands. With the western fleet destroyed and House Lannister fearing another Ironborn landing, Lord Alyn agreed to leave a third of his ships, under Ser Leo, off the western coast while the Lannisters and Farmans rebuilt what had been lost.

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.