During the final battle of the Great Sith War the regiment was deployed to Yavin 4 to act as a vanguard force for the joint Jedi Order and Republic Navy assault on the jungle moon. The regiment fought against the massed Massassi warriors and called down targets for the orbiting Republic fleet while the Jedi force engaged Kun's elite forces directly. It was during this battle that Tuffass, the first Gand to serve in the Republic armed forces, was grievously wounded. In 3,988 BBY during the Corps' reorganization, the regiment was pared down and reformed as the 12th Marine Battalion.