In 2368, the Excalibur was put in for repairs at Starbase 234, and much of the ship's crew was reassigned. Later that year, the ship was selected for a mission into Klingon territory. The mission commander, Captain Jean-Luc Picard, selected Commander William T. Riker as the ship's commander. His first officer was Lieutenant Commander Geordi La Forge.
In the mission, the Excalibur joined Picard's fleet which blockaded the Klingon-Romulan border during the Klingon Civil War. The ship was one of twenty-three assembled for the fleet and was one of the seventeen chosen for the tachyon network. Identified by its name and registry number, the ship's position in the network was monitored from the USS Enterprise-D.
A plan was hatched by Picard, which he hoped would lure the Romulans through the detection grid. When Gowron launched a full attack against the forces of the House of Duras, the Romulan ships would rush to their aid. During this, the Excalibur would fall back with feigned engine troubles, taking the USS Akagi and the USS Hornet. In doing so, this would open up a small gap in the detection net for the Romulans to attempt to pass through. As their ships passed through the gap, the Enterprise-D and the USS Tian An Men would swing around, close the gap, and catch the Romulans in the act.
The plan was foiled when the network was disrupted by a high-energy burst released by the Romulans, the net was no longer effective in a radius of ten million kilometers around the USS Sutherland. Subsequently, Picard ordered the fleet to proceed to Gamma Eridon at maximum warp, where the fleet attempted to reestablish the net before the Romulans got there. (TNG: "Redemption II")
In the late 2360s, the Excalibur survived an attack by the Borg during a night shift. Several members of the crew, including Marika Wilkarah, were assimilated in the encounter. (VOY: "Survival Instinct")
The Excalibur was a reuse of the USS Enterprise-C studio model with the modifications introduced on the USS Zhukov.  New footage of the Excalibur was briefly seen as the fleet departed for the Klingon border; however, some stock footage from "Yesterday's Enterprise" was also reused.
According to the Star Trek Encyclopedia (4th ed., vol. 1, p. 254), the Excalibur was attacked by the Borg in 2368.
The Excalibur became the star ship of Peter David's Star Trek: New Frontier novel series and was later destroyed and replaced with a new Galaxy-class starship USS Excalibur-A (β). Captain Morgen (β), a former crewmate of Captain Picard's from his days on the USS Stargazer, was mentioned as having commanded the Excalibur for many years in Michael Jan Friedman's novel Reunion. It was then commanded by Captain Morgan Korsmo (β) just before the start of the New Frontier series. Korsmo was an old Academy classmate of Picard, but he was killed fighting the Borg during the Battle of Sector 001. Following the vessel's refit, command of the Excalibur was given to Captain Mackenzie Calhoun (β).