Duke is the field leader of the G.I. Joe Team. He is a well respected leader and does what he can to bring home the men and women serving under him. He is known for his gallantry and is not afraid of any fight even with the odds against him. He will find a way to victory.
Duke was a member of a unit stationed in the Middle East. On a routine patrol, his unit was ambushed. Despite the loss of 70% of their vehicles and several men, he was able to bring the fight back to their attackers. An action that brought him to the attention of Hawk who recruited him to the Joe Team. 
On one of his earliest assignments for the Joe Team, Duke was on a mix of a training and an actual mission. Despite some vague references on what the actual mission was, he and Scarlett with the help of a civilian figured they were to rescue Snake Eyes from Chimera. They find out that Chimera aims to topple the United States with an assault on two fronts. They tracked him to an abandoned base in the Nevada desert. Despite the odds stacked against his team, he leads them to overcome Chimera’s men.
- Duke has 3 Purple Hearts and 2 Silver Stars.
- Duke has a sister in Spokane, Washington.
- Although it is inconsistently portrayed, Duke has a scar on his right cheek.