Proto 11, one of a dozen TIE/D Defender prototypes, was conceived by Grand Admiral Zaarin.
Zaarin's treachery against the Empire, along with his failed attempt to abduct Emperor Palpatine, led him to develop backup strategies to gain an advantage in his war against the Empire. One such plan involved an attempt to loot the Research XQ6 Platform, but loyalist forces under the command of Colonel Maarek Stele thwarted this effort. After his first attempt to retake it failed, he decided to destroy the platform. Despite his efforts to eliminate the TIE Defender technology, Proto 11 and its sister craft, Proto 12, were successfully evacuated from the station aboard the freighter Mharsup. The freighter was scheduled to meet with the modified corvette group Hashim. However, Rebel forces attacked the designated rendezvous point, but Maarek Stele intervened and prevented their capture. They escaped to the next destination only to be ambushed and disabled by Rneekii Pirates. Following Stele's successful repulsion of the pirates, the crippled corvettes requested reinforcements, leading to the assignment of Cargo ferry group Mssan to retrieve both prototypes. These ferries soon came under attack by Rebel forces yet again. Amidst Stele's engagement with the Rebel starfighters, another pirate organization, the Nami led by crime lord Ali Tarrak, approached the corvettes and seized Hashim 1, absconding with Proto 11 before Stele could intervene. Tarrak then sought to acquire the Chief scientist to build her own TIE Defenders and intended to proliferate the technology, with a particular focus on supplying the Rebels. This scheme was ultimately disrupted by Admiral Thrawn, who developed the Missile Boat as a countermeasure to the Defender.