Mandalore campaign

In late 20 BBY, Republic forces launched an invasion of the Mandalore system led by a number of Jedi Generals and clone commanders with the intent of occupying the system and restoring the New Mandalorian government's control over the area. Imperial Period historians later referred to the campaign as the "Siege of Mandalore".

Prelude
In early 20 BBY, a deserted clone ARC trooper known as Spar claimed the title Mandalore the Resurrector and, with an from an army of Supercommandos and warriors of numerous clans, secured his dominion over Mandalore. Following his rise to power after Duchess Satine Kryze's death, Spar formed a loose alliance with the Confederacy of Independent Systems and provided a number of Supercommandos to serve on numerous Separatist battlefronts as shock troopers. It wasn't long until the Galactic Senate learned of these events and in retaliation deployed several clone battalions and a fleet of Venator-class Star Destroyers.

The campaign
During the campaign, Republic forces met fierce resistance from the local population, particularly the many Supercommando militias and clans that operated throughout the system. The Mandalorians also received support from a Separatist droid army created from a local factory. While the clone troopers managed to secure many Mandalorian settlements and fortifications across Mandalore and its moon Concordia, many cities such as Keldabe and their surrounding regions remained under Mandalorian control. As each Mandalorian group used their own tactics ranging from guerrilla warfare to interdiction, Republic strategists were unable to accurately predict and react to enemy movements. The clone troopers on Mandalore were supported by AT-AT walkers, Y-wing bombers, and BARC speeders, while the Mandalorians used a number of improvised combat vehicles and Separatist-provided STAP speeders. The 501st Legion also briefly participated in the campaign.

In space, the Republic saw greater progress as they were able to defeat the Mandalorian corvettes and gunships in the area, with a majority of their resistance coming from pirate ships that were not even involved in the conflict. After securing Mandalore's aerospace, the Republic locked down the area to civilian travel and occupied the orbiting space stations.

Aftermath
Mandalorian forces were hold some ground long into the Imperial Period; the conflict continued to rage on between Mandalorian and Imperial forces until the Imperials were forced into withdrawal in 3 ABY. While the invasion was extremely costly and lasted more than two decades, many Mandalorians saw it as a blessing in disguise as the invasion delayed any conflicts that were raging between Mandalorian factions.