Duke was a human male who served as a pilot in the Alliance to Restore the Republic and flew under the callsign Phoenix Five during the Attack on Lothal. Duke perished when he was shot down and killed by the Imperial Commander Vult Skerris in his TIE/D Defender Elite as he was attempting to break through the blockade.
Duke was a Rebel Alliance T-65B X-wing starfighter pilot during the Imperial Era. In 1 BBY, he was part of General Hera Syndulla's strike team that attempted to take out the Imperial Armory Complex and nearby fuel depot on the planet Lothal. This was part of Syndulla's plan to halt Grand Admiral Thrawn's TIE/d "Defender" Multi-Role Starfighter production programme. During the attack, Duke answered to the callsign Phoenix Five and flew with Cleat, who answered to the callsign Phoenix Four.
After Hera's strike team exited hyperspace and encountered Thrawn's 7th Fleet, Hera ordered Phoenix Five and Phoenix Four to thin out the approaching TIE fighters. Duke and Cleat complied with Hera's orders. When Cleat told him to keep up, he responded affirmatively. As the two were attacking TIE fighters, the Imperial ace pilot Vult Skerris entered the dogfight in his TIE/D Defender Elite behind Duke's X-wing starfighter. Cleat tried to warn him but Skerris shot down his fighter, killing him. Skerris then went on to kill Cleat before being taken out by Syndulla.
General Syndulla's strike team was wiped out by Thrawn's strong TIE fighter defense with Hera herself being captured. Despite the failure of the initial assault, Duke's sacrifice was not in vain since the Spectres subsequently succeeded in knocking out TIE Defender production on Lothal when Governor Arihnda Pryce fired on the Lothal City fuel depot in an attempt to destroy the rebel cell.
Duke first appeared in "Rebel Assault," the ninth episode of the fourth season of Star Wars Rebels. He was voiced by Freddie Prinze Jr., who also voices Kanan Jarrus. He has the same animation model as Gold Four from "Secret Cargo."