The clash known as the Battle of Vanquo unfolded in the year 3964 BBY. During this time, the Mandalorian Neo-Crusaders launched an assault on Vanquo, a mining world situated in the Outer Rim. This event marked the commencement of their war against the Galactic Republic. Positioned as a resource-rich planet in proximity to Taris, the ecumenopolis that the Mandalorians truly sought, Vanquo was a component of the Jebble-Vanquo-Tarnith line, a Republic defensive arrangement intended to shield Taris from Mandalorian incursions. Despite this, the Mandalorians initiated their attack on Vanquo as part of a comprehensive three-pronged strategy aimed at seizing Taris. Mandalore the Ultimate, the leader of the Neo-Crusaders, strategically orchestrated the Vanquo engagement to divert the Republic Navy's attention from its left flank, thereby forging a path toward Taris. Squads composed of Mandalorian shock troopers swiftly gained control of the mining facilities located on Vanquo's nightside, while the Mandalorian and Republic fleets engaged in intense space battle in the skies above. Ultimately, Captain Saul Karath of the Republic was compelled to withdraw, resulting in the planet's conquest by the Mandalorians. The Mandalorian triumph at Vanquo furnished the Neo-Crusaders with a stronghold in the Outer Rim that they maintained indefinitely, and it also paved the way for their subsequent conquest of Taris shortly thereafter.
In the year 3976 BBY, the Mandalorian clans of warriors, under the leadership of Mandalore the Ultimate, embarked on a campaign to establish an empire through the conquest of independent worlds situated in the Outer Rim, without provoking a response from the Galactic Republic. After accumulating a substantial amount of territory, the Mandalorian Neo-Crusaders extended their reach toward the Core, encroaching upon Republic space and posing a threat to resource-rich planets in the vicinity of Taris, the ecumenopolis. Among the planets targeted by Mandalore was Vanquo, a harsh mining planet that had become a haven for refugees fleeing the Mandalorian crusades.
As the Mandalorian threat loomed, Vanquo was integrated into the Jebble-Vanquo-Tarnith line, a Republic defense perimeter. This line, intended to safeguard Taris, witnessed prolonged and stalemated conflicts on planets such as Suurja. However, in 3964 BBY, the situation underwent a significant shift. At Taris' Jedi Tower, four out of the five Padawans undergoing training to become the next generation of Jedi on the planet were murdered, allegedly by Zayne Carrick, the sole surviving classmate. Following Carrick's escape and flight from the planet, public trust in the Jedi Order was severely undermined, leading the Jedi High Council to recall the five Jedi Masters stationed at the Jedi Tower back to Coruscant. Mandalore the Ultimate interpreted this as a signal to commence his offensive, launching a three-pronged assault with the objective of capturing Taris. Thus, the true Mandalorian Wars began.

Mandalore's strategic intent was for the Vanquo attack to serve as a feint, aimed at drawing away the Republic fleet's left flank and clearing the path for the Mandalorians' primary advance toward Taris. To achieve this, the Mandalorians initiated a substantial landing force on the planet's nightside, led by Commander Rohlan Dyre, who had a history of desertion charges. The shock infantry descended upon the mining camps scattered across Vanquo's mountainous terrain, utilizing Basilisk war droids, scout speeders, Meteor-class Q-Carriers, and Shaadlar-type troopships for transportation. At one outpost, a Mandalorian contingent, including Dyre, unexpectedly encountered the fugitive Zayne Carrick and his companions, who had previously staged a fake Mandalorian attack on the outpost to facilitate scavenging. The group was caught off guard, and Jarael, an Arkanian Offshoot who had been impersonating a Jedi in their previous scheme, was taken prisoner aboard a Teroch-type gunship. Amidst the ensuing chaos as the others attempted to escape, Dyre seized the opportunity to flee the battle in the group's ship, The Last Resort. Carrick's group pursued Dyre as he headed toward orbit, with The Last Resort subjected to intense Mandalorian blaster fire. Nevertheless, Dyre successfully piloted The Last Resort out of the Vanquo battle zone.
Apart from this incident, the battle proceeded smoothly for the Mandalorians. The shock troops encountered minimal resistance at the mining camps, and Cassus Fett, Mandalore's lieutenant, reported the establishment of an orbital screen over the planet's dayside to engage the major settlements there. Furthermore, the Mandalorians successfully diverted the Republic Navy's flank. Concurrently, a fierce space battle unfolded over Vanquo, as numerous Mandalorian Kyramud-type battleships clashed with Republic Hammerhead-class cruisers. The Hammerheads launched flights of Aurek-class tactical strikefighters that engaged squadrons of Mandalorian Davaab starfighters. Admirals Jimas Veltraa and Noma Sommos led the Republic forces, coordinating the defense against the full force of the Mandalorian assault on Taris. At Vanquo, Captain Saul Karath commanded the Republic defense fleet from his Inexpugnable-class tactical command ship, the Courageous, which formed the center of the Republic line. Despite Karath's valiant defense of Vanquo, he was eventually compelled to retreat, allowing the Mandalorians to seize control of the planet.
The Mandalorian conquest of Vanquo not only provided the Neo-Crusaders with a secure foothold in the Outer Rim, which they would retain, but it also facilitated their subsequent attack on Taris. With the Jebble-Vanquo-Tarnith line breached, Republic Admiral Jimas Veltraa reorganized the remaining Outer Rim fleets into a defensive line to protect Taris. However, the Mandalorians still managed to capture Taris, resulting in Veltraa's death during the destruction of his flagship, the Reliance. Saul Karath's resolute defense and strategic retreat from Vanquo significantly advanced his career, leading to his promotion to admiral following the battle.
The Battle of Vanquo was first depicted in Knights of the Old Republic 7, a comic authored by John Jackson Miller and released in 2006. The narrative continued in the series' subsequent issue, and the battle's outcome, along with additional details, were provided in the supplements The Admiral's List: Jimas Veltraa Memorial Edition and the 2009 reference book The Essential Atlas. The term "Battle of Vanquo" was first used in the 2008 Knights of the Old Republic Campaign Guide.