The Citadel was built in 550 BC to ensure the security of it Homeworld and it colonies. The Citadel was a critical asset for the Asiaguard for the coming 2 millennia later as it would fight off multiple attack from an unknow enemy. In 2620 it would act critical during the War for the Mantle of responsibility as it served as the military Headquarter of the UNSC Asiaguar Sangheilian alliance. It would be later deployed in the sol system to ensure the protection of Earth.