The Treaty of Alderaan was a document signed by the planet Alderaan in the early days of the Galactic Empire. The treaty stated that Alderaan would rid itself of all weapons. Alderaan followed the terms of the treaty for years. Circa 2 BBY, however, the Sith LordDarth Vader fabricated evidence that Alderaan had violated the treaty and was stockpiling weapons for use against the Empire. Vader then used this evidence to invade Alderaan, part of his plan to capture Viceroy Bail Prestor Organa and, ultimately, Princess Leia Organa.