The Tartarus System was used as a prison for captured High Guard vessels after the First Systems Commonwealth Civil War. The star in the system is a brown dwarf supernova remnant. There are no raw materials in the system and it is difficult to slipstream into and out of the system. ("The Knight, Death, and the Devil")
During the Nietzschean Rebellion, dozens of High Guard vessels were captured by the Nietzscheans and placed in Tartarus. They hoped to erase their Artificial Intelligences so they could be reprogrammed and be used in future battles. The Artificial Intelligences were too strong to overcome, and the Nietzscheans made numerous attempts to get rid of the Artificial Intelligences - program invasions, viruses, and other methods - but had no success.
The ships created a single Slipstream drive and installed it on Clarion's Call. He was to follow a leaving patrol and forge an alliance with the enemies of the Drago-Kazov Pride. He was lost in the tangled webs for 100 years before he finally exited, and was converted into a casino by the Nightsiders. His escape resulted in the destruction of two supply vessels, taken apart piece by piece.
200 years later, the system is ruled by the Drago-Kazov Pride and they had created a successful Artificial Intelligence eraser. Captain Dylan Hunt of the Andromeda Ascendant learned of this and located Tartarus with the help of Ryan, the avatar of the Clarion's Call.
Captain Hunt asked the ships to come with him to provide assistance in the restoration of the New Systems Commonwealth, but many of the ships refused to serve the government who had forgotten them. The Dragans were able to use the Eraser on the Wrath of Achilles. The other ships considered destroying Achilles so it wouldn't fall into the Nietzscheans' hands. Dylan gives them the choice of joining a new High Guard or not. Having been given the choice, the ships chose to join Dylan on his quest. As a result of Achilles's Artificial Intelligence having been erased, Ryan enters the Virtual Reality matrix of the Wrath of Achilles and installs himself as the new Artificial Intelligence.
Upon the arrival of an entire fleet of Dragan warships, some of the ships, including the Million Voices, decide to run interference for the other ships giving them a chance to escape the system. Dylan told her Artificial Intelligence Milla she didn't have to do that, but she told him in response that it was her choice and that all she ever wanted was the right to choose.
- Tartarus was the area of the Greek underworld where the worst torture was inflicted. It was also the place where the most powerful of evils were imprisoned, such as the Titan Kronos.