Captain Din was the commander of the Victory-class Star Destroyer Zeplin some time before the Battle of Endor. Din served under Grand Admiral Zaarin, who later led a failed coup against Emperor Palpatine.
While Zaarin generally detested the Rebellion, Din grew sympathetic to the cause of the Rebel Alliance during his tenure as the warship's captain. Having full knowledge of Palpatine's trap for the Rebels at Endor, he arranged to defect with his ship and the Missile Boat Sealion. After meeting up with the Mon Calamari Star Cruiser Link, the missile boat was transferred to the Rebel ship.
Unfortunately for Din, however, the Imperial-class Star Destroyer Garrett, along with Darth Vader and Maarek Stele's forces flying Assault Gunboats, soon arrived at the rendezvous point. The Link managed to escape into hyperspace, however, with the Sith Lord in hot pursuit. Meanwhile, in the battle that followed the remaining Imperial forces succeeded in disabling the Zeplin. Several transports carrying Imperial troops boarded the Star Destroyer and captured Din, who was to be brought before Lord Vader for interrogation.