The Vanguard, under the command of General Jan Dodonna, served as an EF76 Nebulon-B escort frigate within the Rebel Alliance's fleet. As part of his unit, Dodonna, piloting the Vanguard along with other ships, journeyed to the planet Atollon in 2 BBY (in the year calendar), the home of the Phoenix Cell Rebel group. Together, Dodonna's forces and Phoenix Squadron, under the leadership of Commander Jun Sato, formulated a plan to strike at an Imperial factory situated on Lothal. However, the grand admiral Thrawn of the Empire discovered the location of the Phoenix Squadron's base, and brought his fleet to Atollon, aiming to crush the Rebellion. During the resulting battle, the Vanguard met its end, although Dodonna and a portion of the crew managed to escape just before the ship's destruction.
The EF76 Nebulon-B escort frigate known as the Vanguard was a product of Kuat Drive Yards. As a frigate of the Nebulon-B class, the Vanguard possessed an arsenal of twelve turbolasers in addition to twelve laser cannons. These primary turbolaser and laser cannon emplacements were situated at the lower end of the ship's forward section. Moreover, the frigate featured a minimum of eight escape pods, potent dual tractor beams, and a main communications array found on the port side of the upper portion of the Vanguard. Certain areas of the frigate's exterior were painted in red and yellow hues.
Located in the center of the bow was the Vanguard's bridge, equipped with several computers and seating for the crew, a central holotable, and stairs with railings that led to an elevated platform. From this vantage point, General Jan Dodonna, the commander of the Vanguard, issued commands during combat scenarios.
The Vanguard, along with other Nebulon-B frigates, was constructed by Kuat Drive Yards. These ships were then obtained by the Alliance to Restore the Republic to aid in their conflict with the Galactic Empire. At least three of these frigates, including the Vanguard, served under General Jan Dodonna in the Massassi Group Rebel unit during 2 BBY.
Dodonna's Massassi Group collaborated with the Phoenix Cell, another Rebel unit, to devise a strategy to attack an Imperial factory located on the planet Lothal. This factory was responsible for the production of various Imperial vehicles, ranging from TIE fighters and walkers to the newly developed TIE Defender. Once prepared for the assault, the Vanguard and the rest of Dodonna's ships jumped to Atollon, an Outer Rim world that hosted the base of Phoenix Squadron. Commander Jun Sato, the leader of Phoenix Squadron, who was aboard the Rebel cruiser-carrier Phoenix Nest, contacted the Vanguard and welcomed Dodonna to the planet. The general expressed his gratitude to him, eager to finally launch a significant attack against the Empire.
The Imperial Grand Admiral Thrawn had, unknown to the Rebels, discovered the Alliance's intention to strike the Lothal factory. By monitoring Dodonna's fleet movements and intercepting a transmission from Imperial Security Bureau agent Kallus, a "Fulcrum" operative within the Rebellion, attempting to warn the Rebels about Thrawn's knowledge of their plan, he pinpointed the location of Phoenix Squadron's base. Dodonna, still on board the Vanguard, communicated with Phoenix Squadron via hologram and received Kallus's transmission. The message was cut short, preventing Kallus from revealing what Thrawn knew. However, Ryder Azadi, the leader of a resistance on Lothal, informed them that the Imperial fleet had departed the system. Rebel captain Hera Syndulla correctly inferred that Thrawn was aware of their base's location, and moments later, Thrawn's Seventh Fleet emerged from hyperspace above Atollon. During the ensuing battle, the Vanguard was destroyed when Syndulla ordered a full retreat to the planet's surface, with survivors escaping in escape pods.
During the battle of Atollon, the Vanguard was under the command of General Jan Dodonna, a human male hailing from Commenor. The frigate's bridge crew during the battle consisted of a minimum of five Rebel soldiers.
The animated television series Star Wars Rebels featured the Vanguard in the twenty-first episode of its third season, entitled "Zero Hour." This episode was broadcast on Disney XD on March 25, 2017.