Preston Greenfield

Preston Greenfield is a minor character in Game of Thrones. He is played by an uncredited background actor. The actor has not been identified. He is a member of the Kingsguard and defends King Joffrey Baratheon as he defended King Robert Baratheon before him.

Season 1
He was among the guards that attacked Eddard Stark when he tried to de-throne King Joffrey.

In the books
In the Song of Ice and Fire novels, Greenfield is a member of Robert Baratheon's Kingsguard. He is noted as the shortest member of the Kingsguard. He accompanied Robert on his boar hunting trip where he was mortally wounded. He transfers his loyalty to Joffrey following Robert's death.