In an alternate mirror universe, William T. Riker was a Terran male who served in the Imperial Starfleet in the late 24th century.
Born in Alaska, Earth in 2335, Riker entered Imperial Starfleet Academy in 2353 at the age of 18. Following his graduation in 2357, he went on to serve aboard several starships including the ISS Pegasus, the ISS Fortuna, the ISS Yorktown and the ISS Hood.
By 2364, he had successfully rose to the rank of commander and served as first officer aboard the Hood.
Despite having the opportunity to assassinate Captain Robert DeSoto and gain command of the Hood, he instead sought the chance to serve as first officer aboard the flagship ISS Enterprise-D, under the command of Jean-Luc Picard. Over the next several years, Riker made several assassination attempts against Picard, but the older man proved too cunning and outwitted Riker on several occasions. Although, Picard was keen to kill Riker, his supporters at Starfleet Command proved too powerful to see such action pass without incident, and even several attempts to promote him to the captaincy of the ISS Aries and ISS Melbourne, proved futile. Riker had his sights set on commanding the Enterprise and he was unshakable.
In early 2370, Riker was promoted to Commodore by Empress Sato and given command of the ISS Constellation. Following the destruction of the ISS Thermopylae during a Xindi ambush, the ISS Constellation, under the command of Riker, was then ordered to locate and secure the weapon for Empress Sato. Riker and his crew were able to to locate and secure the weapon for Empress Sato.
Following the mission Riker was demoted to Commander and sent back to the Enterprise as first officer.
However, in early 2371, Riker's reputation took a knock when the Enterprise was destroyed by Klingon renegades in the Veridian system while he was in command of the ship. Picard saw this as the best possible opportunity to eliminate Riker once and for all, but his supporters again blocked any attempts. While Riker was expected to be severely punished for his gross negligence, he was instead absolved of any responsibility and promoted to the rank of captain and given command of the ISS Voyager.
In 2371, Riker took command of the ISS Voyager. Unfortunately, Riker was killed by Picard and his allies 3 months into his command of Voyager in the Archer system after an attack on Voyager by officers loyal to Picard and Empress Sato.