Anastasius was a planet from within the Unknown Regions of the galaxy, and existed as one of the last creations―along with Vyselennaya―of the World Builders, an ancient species known as the Xaxax. At some point, Anastasius was believed to have been associated with the ancient Gree Enclave, due to the presence of a Hypergate that linked the planet to Ilos, which was situated on the far opposite end of the galaxy.