Inexpugnable-class tactical command ship

Featuring a disc-like form with a central aperture, the Inexpugnable-class tactical command ship was often compared to a mobile space station due to its substantial 3,100 meters diameter. The design of the bridge was particularly innovative; holograms were projected onto a transparent deck, creating a fusion of electronic and visual information to enhance command capabilities. This bridge layout, affectionately dubbed the "wishing well" by Republic helmsmen, occasionally induced vertigo. A complement of 4,300 Republic officers and enlisted personnel operated the Inexpugnable-class, which also accommodated 2,000 troops. It was capable of carrying up to 50,000 metric tons of cargo, along with sufficient supplies to sustain the ship and its crew for a period of two years.

Inexpugnable-class vessels were armed with an array of weaponry, including five double turbolaser batteries, five light turbolaser batteries, two point-defense laser cannon batteries, and two tractor beam batteries. Three turbolaser batteries were positioned on each side of the primary circular structure, with two additional batteries located near the vessel's bridge. Propulsion for the Inexpugnable-class was provided by four large thrusters, powered by engines situated deep within the circular superstructure. For faster-than-light travel, it was equipped with both a Class 2 hyperdrive and a Class 10 hyperdrive as a backup system.

Beneath the main superstructure, towards the stern, the warship featured expansive hangars and a command center. Further hangar bays were located on the vessel's bow, facilitating the rapid deployment of fighters from multiple levels. Adjacent to the ship's brig was a dedicated cargo bay, in addition to the fighter decks. The class was capable of carrying 144 Aurek-class tactical strikefighters and twenty-four S-250 Chela-class starfighters. It could also accommodate smaller transports, specifically twenty-four Conductor-class landing craft and six Ministry-class orbital shuttles. Furthermore, the hangar bays were capable of housing a variety of Republic support vessels.

Within the Republic Navy, the Inexpugnable-class fulfilled the function of a command ship. Its design, a collaborative effort between Rendili Hyperworks and Rendili/Vanjervalis Drive Yards, was strategically intended to boost sales of Hammerhead-class cruisers to the Republic. During the Mandalorian Wars, the coordination of weaponry became a critical concern for Republic tacticians, as the defense of Republic lines frequently relied on numerous Hammerhead-class cruisers. The Inexpugnable-class was engineered with an enhanced sensor suite and an innovative bridge design, enabling a flag officer to oversee a fleet consisting of up to sixty-four Hammerhead-class cruisers concurrently. While the Inexpugnable-class's extensive hangar bays facilitated the swift deployment of fighter squadrons, they also rendered the ship susceptible to ramming attacks and boarding actions. The Centurion-class battlecruiser, a smaller vessel, eventually assumed the role of command ship.

Before the Republic became embroiled in the Mandalorian Wars, the need for a tactical command ship capable of coordinating the large Hammerhead-class fleets defending its territories was recognized. The Swiftsure, a proof-of-concept vessel, was constructed sometime prior to the outbreak of the Mandalorian Wars. Fewer than six Inexpugnable-class prototypes were built before the Mandalorian Wars commenced. They were designed by Rendili Hyperworks and launched from the Rendili/Vanjervalis Drive Yards at Corellia. Costing an estimated 70,000,000 credits, this new series of command ships effectively replaced the Republic's older command ships, such as the Reliance I. The Courageous was among these prototypes. The Indefatigable and the Tremendous were also part of the production run. Republic crewmen affectionately called them "Inexies."

In 3964 BBY, the Mandalorian Wars directly impacted the Republic when Mandalorian fleets launched attacks on Vanquo and Taris. During the Mandalorian Wars, Inexpugnable-class vessels were used by the Republic Navy as large command ships and flagships of battle groups. The Courageous, under the command of then-Captain Saul Karath, led its battle group in opposition to the Mandalorians during the Battle of Vanquo. In early 3963 BBY, at Serroco, Zayne Carrick, a Jedi apprentice accused of the Padawan Massacre, experienced an intense Force vision and subsequently boarded the Conductor-class landing craft Deadweight, piloted by Lieutenant Carth Onasi, to alert Karath to an impending Mandalorian assault. However, Karath, recognizing Carrick as a fugitive, promptly imprisoned him in the Courageous's brig, disregarding the warning. As foreseen, the Mandalorians initiated a full-scale attack on Serroco, employing nuclear missiles to obliterate cities and Republic forces on the planet's surface. Following the assault, the Mandalorians boarded and seized control of the Courageous. Nevertheless, Karath, Carrick, and Onasi managed to escape; Carrick had used the Force to dismantle the wall of his [prison](/article/prison-legends] cell, granting them access to the Deadweight in the Courageous's landing bay. The Mandalorians repurposed the captured Courageous for their own use; Mandalore the Ultimate later asserted that his battle-axe was crafted from the Courageous's hull. The remnants of the Courageous battle group merged with the Tremendous and its own battle group, while now-Admiral Karath transferred his command to the Swiftsure shortly after the First Battle of Omonoth. The Diligence, commanded by Dallan Morvis, was another Inexpugnable-class ship that saw service.

Following the Battle of Serroco, the remaining Inexpugnable-class ships, including the Swiftsure, the Tremendous, and the Indefatigable, were upgraded with a new sensor package enabling the use of tactics such as the Vanjervalis Chain. This advanced sensor system slaved the controls of up to sixty-four Hammerhead-class cruisers, predicted enemy movements, and optimized fleet positioning. The Swiftsure was the first to receive the system from the manufacturers, serving as the prototype for the production model. While in command of the Swiftsure, Karath utilized the Vanjervalis Chain to safeguard the Republic capital of Coruscant from potential attacks or infiltrations, specifically to intercept Carrick, whom the Jedi Covenant believed intended to attack their operations on Coruscant. However, Haazen, the clandestine leader of the Jedi Covenant, gained control over all Republic ships connected to the Vanjervalis Chain. He had directed the Draay Trust to acquire Vanjervalis Systems and integrated fleet remote controls into his Sith artifact, the Gauntlet of Kressh the Younger. He then commanded Karath's fleet, including the Swiftsure, to attack the Republic strike team threatening his plans. The Vindication, Haazen's Jedi Covenant's uprising against the Jedi Order, was thwarted when Carrick and his former Master, Lucien Draay, recovered the Gauntlet of Kressh and used it to order the Swiftsure and the Republic fleet to target both Haazen and the Draay Estate on Coruscant's surface.

Later that year, Karath led the Swiftsure and its task force to an asteroid field near Ithor. Anticipating a Mandalorian assault, the Swiftsure's fleet prepared to engage Cassus Fett, a prominent Mandalorian Field Marshal, and his forces. Fett's fleet engaged the Republic in a brief battle, but the attack was a diversion. Carrick and Fett—who owed Carrick a debt for warning the Mandalorians about the Rakghoul plague on Jebble—orchestrated the false attack to lure out the Crucible slaver ship Gladiator, which Carrick and his friend, Jarael, had previously encountered. Upon learning of the ruse and its purpose, Karath ordered the Swiftsure's fleet to capture the Gladiator and its captain, Dace Golliard. Golliard revealed the location of Osadia, a significant Crucible base where Jarael was being held captive, to the Republic. Karath then detached the Hammerhead-class cruiser Testament from his fleet to investigate, taking Carrick and his associate, Marn Hierogryph, with the objective of dismantling the Crucible and rescuing Jarael.

Due to design flaws, only six Inexpugnable-class vessels, encompassing both prototypes and production models, were ever manufactured. The remaining production was terminated, and the Centurion-class battlecruiser, a smaller alternative, assumed the role of tactical command ship.

The Inexpugnable-class tactical command ship made its initial appearance in the eighth issue of the Knights of the Old Republic comic series. The Inexpugnable-class, along with other new Republic Navy starship classes featured in this issue and the Days of Fear and Nights of Anger story arcs, appeared to share a design lineage with the Hammerhead-class cruiser.

In issue 31, the Inexpugnable-class exhibited a slightly altered appearance. The command ship Swiftsure was depicted with a more pronounced keel and a smaller, rounder primary hull. This variation was partly attributable to artistic interpretation, and also to the fact that the Swiftsure served as the proof-of-concept model.

According to writer John Jackson Miller, the names of Inexpugnable-class vessels were inspired by real-world naval ships. The Courageous derives its name from the French ship Courageux, whose design influenced the construction of four of Lord Horatio Nelson's Leviathan-class ships, a name also associated with Admiral Saul Karath's own command ship in the Star Wars: Knights of the Old Republic video game. The Tremendous was a British naval vessel during the Napoleonic Wars. Additionally, the Royal Navy included ships named Indefatigable and Swiftsure during the same era. The fifth Inexpugnable-class ship, Diligence, was named in the 2011 novel Knight Errant, but the sixth remains unnamed.