Ambrose Pendragon (Morgana)

Ambrose Pendragon is Uther Pendragon's brother and witchfinder.

Season 1
Ambrose Pendragon was the brother of Uther Pendragon. Merlin warned Morgana that Uther's death would lead to Ambrose becoming king. This led to Morgana choosing to save Uther from the sorcerer Muir.