In the mirror universe, the free starship Intrepid was a Memory Omega jaunt ship in service to the Terran Rebellion, and subsequently the Galactic Commonwealth, in the late 24th century. The Intrepid was part of the fleet built by Memory Omega to overthrow the Klingon-Cardassian Alliance. (ST - Mirror Universe novel: Rise Like Lions)
The Intrepid was part of the fleet of jaunt ships - battleships with an in-built wormhole generator - Memory Omega built at Erebus Station, beyond the rim of the Milky Way Galaxy. These ships were given to Terran Rebellion personnel after they had received training on the station.
In the year 2378, the Intrepid and the Courageous were part of the fleet led by Captain Jean-Luc Picard aboard the free starship Enterprise that liberated Andoria from the Klingon-Cardassian Alliance. The fleet left nothing but hulks of the Klingon and Cardassian battleships. Following the battle, Picard had the Intrepid open an artificial wormhole to return the fleet to Erebus. The Enterprise remained at Andoria to aid in the repatriation of free Andorians. (ST - Mirror Universe novel: Rise Like Lions)
In January 2379, the war was over and the fleet of jaunt ships re-launched with missions of defense and peaceful exploration. In July, Commonwealth Assembly settled on a name for their new, democratic nation, the Galactic Commonwealth. (ST - Mirror Universe novel: Rise Like Lions)