Doilan Mellar was one of the mercenaries in Cairhien. He traveled to Caemlyn and was hired to fight for Elayne. His real name is Daved Hanlon. As Doilan, he saved Elayne's life, and became the Captain-General of the Queen's Guard. It is later revealed that he is a Darkfriend and was behind a murder attempt on Queen Elayne.
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