Marwyn Storm is an unseen character in Game of Thrones. He is the only named bastard of Lord Rickard Harrigon.
Marwyn was born near Hornworth and was brought to his fathers home when he was four years old. Lady Lorra Wendwater didn't think anything of Marwyn, as she knew all of the previous lords of Hornworth fathered countless bastard children.
He began his training as a blacksmith in Hornworth at the age of eight.