Tithe: [Nix] Tartarus officially serves as a refueling station for Imperial ships and doesn't have to pay any tithes. De facto Tartarus pays significant bribes to Imperial officials to keep it's status independent.
Population: 2.5 million [2 500 000] (and at least another half a million visitors at any given time)
Government: Anarchy. There are no official leaders in Tartarus. When the time comes to bribe Imperial officials or there is a matter that concerns everyone who resides in the station, a Council of Captains gathers and decides what to do. However everyone agrees that Daikan Alepros is the man to speak to when you want to be heard.
Description: Tartarus, is located in an asteroid cluster near dying star FA-542-LL. Because of it's remote position and lack of centralised government, it is a favourite gathering place for Chartist Captains, merchants, Rogue Traders and pirates to trade, exchange gossip, plan new ventures or get repairs. In 333.M41 Tartarus station attacked visiting Space Marines of the Ghosts of Retribution, severely wounding one.
Technology: [VIII - Mixed] Tartarus, as a place where various captains and traders gather, is overwhelmed by various exotic pieces of technology. As there are no steady supply of replacements for Imperial technology, inhabitants of Tartarus make do with whatever is at hand. You can notice a dock worker bearing an Eldar slasher blade for self-defence, using Xo'nad power stone to get energy for his refrigerator and shaving himself with Imperial Guard issue razor.
Military:Tartarus has unofficial militia that keeps order and would fight if it would come under attack, but it's best defence is hundreds of captains with their ships that need a place like Tartarus to make their deals.
Strategic importance: [Minima] Imperial Navy and respectable merchants avoid Tartarus, but from time to time, when real need arises, they visit it for refueling and repairs. Also Tartarus serves as a good place for Imperial authorities to spy on non-Imperial humans that visit it and even on occasional xenos.
Loyalty: [Separatist 94%] Inhabitants of "Tartarus" are fiercely independent.