Alfred G. Darlton is one of the Glaston Knights' members and adopted son of Andreas Darlton. He is rather smug, though he easily panics under threatening situations.
Alfred's tendency to underestimate Numbers prove to be fatal as his attitude brings him to his death.
Alfred has a minor role in the first season. His first appearance is in episode 21 along with the other members of the Glaston Knights. He also contributes in defeating the Black Knights in the Black Rebellion.
His first appearance in the second season occurs when Zero returns to the Chinese Federation grounds. When the Black Knights go to the execution grounds to free their comrades, he is seen battling several Black Knights. During that time, Alfred is defeated in battle and killed by Kallen Kozuki after he provokes her by saying that Japan does not exist. His death spurs the outrage of his brother Edgar.
(Source: Code Geass Wiki)