In 2277, the Endeavour was assigned to the Taurus Reach and was under the command of Captain Zhao Sheng. Sheng was entirely opposed to his sector commander, Commodore Diego Reyes, but Reyes had kidnapped someone he loved, so he was forced to follow Reyes' orders.
This situation changed when T'Prynn convinced Sheng to lead the Endeavour in an attack against Imperial Starbase 47. The Endeavour took some damage during the attack, but the starbase was destroyed by the Shedai Wanderer. (VAN - Mirror Universe short story: "The Black Flag")