In 4,014 BBY the 20th Marine Regiment's 1st Battalion spearheaded the Republic's effort, approved by the Galactic Senate in the wake of increasing public pressure, to lift the self-imposed blockade of the Ukatis system. This led to a general revolt, supported by the Republic, against the Ukatin king which led to his abdicating the throne. In 3,987 BBY during the Corps' reorganization, the regiment was pared down and reformed as the 20th Marine Battalion.