Order 66, also known as Clone Protocol 66, was one of a series of contingency orders that the clone troopers of the Grand Army of the Republic were trained to obey without hesitation. The order branded members of the Jedi Order as traitors to the Republic and called for their immediate execution without question. The issuing of the order by Supreme ChancellorPalpatine marked the formal beginning of the Great Jedi Purge, and signified the rise of the Galactic Empire. It was chief among the atrocities that led to the Galactic Civil War.