- "Legend has it that Harlon the Hunter and Herndon of the Horn, two sons of Garth the Greenhand, raised the castle in the Age of Heroes, and shared a home and wife for a hundred years."
- ―Randyll Tarly
Herndon was the son of Garth Gardener and brother of Harlon the Hunter. He lived during the Age of Heroes. Along with his brother, he raised the castle of Horn Hill. There he shared the castle and a wife with him. This way of life went on for them for a hundred years, until one of the two died.
In the books
Herndon of the Horn is a legendary son of Garth Greenhand and ancestor of House Tarly. He and his twin brother Harlon of the Horn built their castle atop Horn Hill and took to wife the beautiful woods witch who dwelt there, sharing her favors for a hundred years. The brothers did not age so long as they had intercourse with her whenever the moon was full.