Joffrey Dayne

Ser Joffrey Dayne is an unseen character in Game of Thrones. He was a knight of House Dayne during the War of Conquest.

Biography
When Aegon I Targaryen demanded that Joffrey and House Dayne submit, Joffrey invaded Aegon's realm and marched an army to Oldtown, where Aegon had been crowned.

Reference

 * "House Dayne (Histories & Lore)"