Originally inhabited by the insectoid Killiks, Alderaan's pre-colonial history is lost, save for in the hive mind of the aliens. By the time the first human colonists came to Alderaan from Coruscant‒about 2,500 years before the founding of the Galactic Republic‒the Killiks had migrated into deep space, leaving only a scattered few nests hibernating underground and the empty shells of their hives.
Alderaan's pristine beauty attracted thousands of settlers, and the human colonies quickly developed into thriving provinces. The Alderaanian monarchy made preservation of the environment a top priority in the planet's development, a policy that holds true today.
Later, the planet would become one of the Core Founders of the Republic and among the most powerful voices in the Senate. The princes and princesses of the ruling family typically served as Alderaan's representatives, though other members of the Alderaanian nobility have held the position as well.
Alderaan's recent departure from the Republic and the resulting civil war are among the darkest moments in a bright and optimistic history. Whether the planet will ever regain its former glory is an open question.