FF Fesarius

In the mirror universe, the FF Fesarius was the flagship of the First Federation. The ship was in service in 2293. 

History
On Stardate 9606.2, the Fesarius intcepted the at Theta Cassidium when it trespassed First Federation space on its way to the Janus Vortex. Balok ordered the destruction of the Excelsior and launched buoys and fighters to attack the Terran vessel. Excelsior's fighters destroyed the attacking vessles, and the ship resumed its heading. ( mission: "Balok's War")