By the 37th Millennium Mankind was well-established throughout the region, with an estimated population of roughly five trillion and a thriving local economic infrastructure. However, due to its exposure to the eternal threats of the outer dark along the galactic rim, control of the Sabbat Worlds was ever disputed with the Forces of Chaos and various xenos. Throughout the 38th Millennium, the region suffered a series of brutal wars and conflicts with the barbaric Chaos-worshipping tribes of the Sanguinary Worlds, located further rimwards of the spinward extent of the Sabbat Worlds, and the area soon became known as a "troublesome province" to the Administratum.