The Bastion Fleet, originally known as the Admonitor task force was the personal armada of Grand Admiral Thrawn from 3 ABY until his death in 18 ABY. It was formed from Thrawn's original fleet which he used to map the Unknown Regions from 3 ABY to 6 ABY; during this time, it only consisted of the Imperial I-class Star Destroyer Admonitor, twenty Victory-class Star Destroyers and several support ships. After the Grand Admiral returned to the hidden Imperial fortress world of Bastion, nine other Imperial-class Star Destroyers joined it. This reinforced fleet participated in the initial battles of the Thrawn campaign. In 9 ABY, two Executor-class Star Dreadnoughts were assigned to the fleet, but the iconic Star Destroyer Chimaera retained its role as a command ship.
After the Thrawn campaign ended, the Grand Admiral used the fleet to chart additional territories in the Unknown Regions. This era of expansion ended in 18 ABY with Thrawn's death, and the fleet was disbanded. However, it was resurrected in 40 ABY by the Fel Empire, this time bearing the late Grand Admiral's name.
