The last of the 20 ships to leave space dock before setting out to blockade the Romulans supporting the Duras faction in the Klingon civil war on stardate 45020.4; the Endeavour took a primary position that just mirrored that of the Excalibur. Only months later, under Etana Jol's Ktarian plot to take over the Federation, Commander Riker was to rendezvous with the Endeavour in a shuttle to spread the mind-control game there. It also took part in the battle to repel an invading Borg Cube in the Typhon Expanse in 2373.