Ancients

Name assigned by scholars to a race of highly intelligent, extremely advanced beings which dominated the space in and around the current Third Imperium some 300,000 to 400,000 years ago. Most of what is known about the Ancients has been discovered from archaeological excavation of cities, bases and outposts of their civilization. Current scientific understanding is that the Ancients destroyed themselves in a "Final War" that spanned some 2,000 years.
The influence of the Ancients still shapes the universe today. Most scholars agree that the Ancients took humans and canines from Terra, and transplanted them on many worlds, where their descendants became the Vilani, Zhodani and Vargr. Ancient artifacts show a high degree of technology and sophistication, and have revealed previously undiscovered, uninvented or unexploited technologies.
The Ancients were responsible for several major features within the region now occupied by the Imperium. Their wars resulted in many of the asteroid belts throughout explored space, and there is evidence that they created the multi-world rosette at Tireen (Knaeling 2910, in the Vargr Extents). Scattered empty cities, most showing extensive battle damage still stand as evidence of their wars. Most of these areas are under Interdiction by the Imperium, and not open to the public. One notable exception is the world known as Antiquity . The Antiquity Ancients site is open to tourists, and its museum has many wondrous and mystifying artifacts on display, many of which are still in working condition.