The original USS Republic, NCC-106, was of the Daedelus Class. Launched in 2146, it served for 15 years before it was destroyed by the Romulans in 2161 during the epic Battle of Cheron.
The next Republic, the NCC-106-A, was the third Excelsior Class built and a participant in the failed Transwarp experiment. She survived 70 years and 33 major battle engagements before being lost to the Romulans in the Neutral zone.
recent Republic, NCC-106-B, is of the controversial Prometheus Class.
The original Prometheus was stolen initially by Romulans before being
recovered by a Federation Task Force