The extremist Mandalorian splinter group known as the Death Watch utilized this secret location on Mandalore's satellite, Concordia. This occurred during their resurgence, which was spearheaded by Pre Vizsla. Vizsla, who was the governor of Concordia, made the Death Watch's central hub within some of the mines that were no longer in use. These mines were relics of Concordia's past, from the era when beskar extraction was a widespread practice. Within this location, the Death Watch could leverage the pre-existing mining equipment to produce protective gear and weaponry for their soldiers. Around 21 BBY, the hidden base of the Death Watch was discovered by Jedi Master Obi-Wan Kenobi. He was taken as a prisoner and confined within the mining and production facility connected to the base. He was later liberated by Duchess Satine Kryze, who was the leader of Mandalore's New Mandalorian faction. As they made their escape, Kenobi engaged in combat with numerous Death Watch warriors before facing off against Pre Vizsla in battle. The Jedi Master gained the advantage in this fight until three Death Watch troopers entered the fray. Faced with overwhelming odds, Kenobi and Kryze were compelled to retreat. However, even after the discovery of their base, the Death Watch continued their operations from the Concordian location. It was there that Vizsla amassed a Death Watch fighting force in preparation for an overthrow of Mandalore. This takeover was to be supported by the leader of the Confederacy of Independent Systems, Count Dooku. However, when the Count's scheme failed, he instructed his Death Watch allies at the base to stand down and await a more opportune moment to strike with their forces.
The secret headquarters of the Death Watch on Concordia was situated within one of the mines that had been abandoned. These mines were constructed on the satellite centuries before the Clone Wars. The base primarily consisted of a collection of buildings with curved roofs. It was located at the bottom of a circular mining pit. These buildings featured holocharts and holographic communication hubs. The Death Watch's fleet of Kom'rk-class starships/transports were often seen parked on the ground surrounding the central structure. Connected to the above-ground base, and accessible via a nearby elevator, was a mining and processing facility. In this facility, the Death Watch repurposed the remaining machinery to manufacture protective suits and rocket packs for their troops.
Concordia initially served as an agricultural settlement for the Mandalorians. However, prior to the conclusion of Mandalore's wars, the Mandalorians transformed their moon into a location for extraction in search of beskar. Beskar is a nearly indestructible metal that can withstand strikes from a lightsaber. The extensive mining operation and its numerous mines were eventually deserted, and over the years, they remained silently inactive. However, following the demise of Death Watch leader Tor Vizsla at the hands of Mand'alor Jango Fett, the radical and violent Mandalorian splinter group fragmented and disappeared from the galaxy under the Mandalorian principle of ba'slan shev'la, meaning "strategic disappearance." Years later, Pre Vizsla, a fellow member of Clan Vizsla, rose to prominence as the new leader of the Death Watch as it began its return to the galaxy. The younger Vizsla held the position of governor of Concordia and was publicly a staunch supporter of the peaceful New Mandalorian faction, as well as a friend of the New Mandalorians' leader, Duchess Satine Kryze. In reality, Vizsla harbored contempt for both Kryze and her pacifistic government. Within one of the abandoned mines scattered across Concordia's surface, Vizsla secretly established a base from which the Death Watch could regroup and operate in opposition to the New Mandalorians. There, the Death Watch forces made use of the abandoned industrial equipment left behind by the miners in the process of crafting Mandalorian battle armor and weapons for their troops.
During an investigative mission to Mandalore early in the Clone Wars—a conflict spanning the galaxy between the Galactic Republic and the Separatist forces of the Confederacy of Independent Systems—Jedi Master Obi-Wan Kenobi discovered the Death Watch's base while attempting to determine if the believed-to-be-inoperable mines were actually functioning. He was ambushed, overpowered, and captured by a pair of Death Watch soldiers. However, before his execution, Kenobi was rescued by Duchess Kryze, and the two headed for the surface, unknowingly walking directly into the main area of the Death Watch's base camp. They sought cover behind a pile of rocks as a group of Death Watchmen opened fire with blaster rifles, and three more attacked the Jedi Master from the air using jetpacks. Kenobi defeated the commandos equipped with jetpacks, while the remaining Death Watch troops evacuated the area aboard their Kom'rk-class starships/transports. They were then confronted by the Death Watch's leader, Pre Vizsla. Vizsla and Kenobi engaged in a duel using lightsabers—Vizsla wielding the black-bladed Darksaber that had been passed down within his clan—and when Vizsla's abilities proved insufficient to defeat Kenobi, three of his troops attacked the Jedi Master with missiles launched from their jetpacks. Faced with overwhelming odds, Kenobi fled the base with Kryze.
Despite Kenobi's exposure of the Death Watch's base, the Mandalorian radicals continued to utilize it in later times. It was at this location that Vizsla assembled a Death Watch military in preparation for a Separatist-backed takeover of Mandalore. The plan involved a Republic occupation of the planet, which would then allow the Death Watch to present themselves as liberators of the people. To the Death Watch's disappointment, and Pre Vizsla's considerable anger, the Republic did not dispatch a force of clone troopers to Mandalore. Knowing that the Death Watch lacked the strength to hold the planet against the will of the Mandalorian people for more than a day, Separatist leader Count Dooku ordered the assembled army at the base to stand down until a later time.
By the time of the Galactic Civil War, the Concordian base was no longer the Death Watch's primary headquarters. The Death Watch had relocated the majority of their operations to a new facility, which was established within a bunker on the forest moon of the Outer Rim world, Endor.
The Death Watch's hideout on Concordia made its initial appearance in the twelfth episode of the Star Wars: The Clone Wars television series' second season, titled "The Mandalore Plot." The Concordia base is the second Death Watch installation introduced in Star Wars canon, following the Death Watch bunker on Endor, which was introduced in the online MMORPG, Star Wars Galaxies.
During the opening scene of "The Mandalore Plot" at the base, a holochart can be seen behind Dooku's hologram displaying the words "TARGET: PEACE PARK" in Mando'a letters. This foreshadows the destruction of the Peace Park's memorial shrine in the subsequent scene.