Great Day of Victory

The Great Day of Victory, was the day in 4,018 BBY when the 3rd Mandalorian Crusaders troopers conquered all the major republican worlds, causing the Galactic Jedi Republic to be fragmented, and get reorganized in to the Galactic Jedi Republic Remnants, thus leaving the Mandalorian government the dominant galactic government. This allowed the Mandalorians to unite with the Sith Empire Remnants and create the Galactic Union.