The marines are the best clone troopers we have out there. Let's not waste them, shall we?
—Tavo Zirátæ
The Republic Marine Corps was a legion of the Grand Army of the Republic composed of the best clone troopers in the Army. These men, designated Advanced Clone Troopers (ACTs), were given modified armor and advanced training in military and naval techniques and tactics. Originally called the Advanced Clone Trooper Combat Elite Unit, the legion, under the command of Commander Jesse revived the name of the Republic Marines of the Mandalorian War.
Living up to their title under General Drewika Zirátæ's command, the Marine Corps fought in many land and space battles in the Clone Wars. Following the execution of Order 66, the Republic Marine Corps were given new armor and weapons, but were allowed to keep their name.
They were equipped with DC-15 heavy blaster rifles, a portable missile launcher, grenades, and specialized armor, all of which aided them in their battles against the droid forces of the Confederacy of Independent Systems.