Anyone else consider the idea that the nebula beyond Gamma Draconis was possibly once a major Ancient system?
I think the Sathanas fleet was the core force that killed the Ancients, with the Lucifers, Demons and Ravanas being second-line ships (much like the Hatshepsuts, Orions and Hecates are the lead GTVA force, with the Deimos and Sobek corvettes doing most of the dirty work around the time of FS2 [For example, when did the Aquatine ever do anything combat-wise, except when it was attacked?]).
We know that, as the Ancients expanded their empire, using Knossos Devices to create new nodes, they run into the Shivans. Someone shoots first, and then the Ancients manage to get the Shivans really upset (or some Shivan admiral said "Oooh. A nice new target. Lets kill them"). Either way, the Shivans now chased the Ancients through space.
It took the GTVA three decades or so to build the Colossus. Even if the Shivans have more advanced construction methods, I still can't see a Sathanas taking less than a decade to build. So, assuming they had 10 Sathanas-capable shipyards, that's a minimum of a century to build the Capellan fleet. And I don't think they would have thrown everything they had into Capella. This means that the Sathanas project was underway before the Terran-Vasudan war began.
Given currently known Shivan ships, we have the choice of Lucifers or Sathanas killing the Shivans. We know from the monologues that the Lucifers were at least a significant threat (as there was the whole shields-don't-work-in-subspace bit). But, I don't see Lucifers alone being the only threat.
We know one Lucifer was created, and destroyed in the node to Sol. (My personal opinion is that the Lucifer fleet was a backwater 'garrison' force, who gathered that there was trouble brewing by detecting the TV war, and decided to gain some glory by killing the upstarts.) Yet given the scale of what we know the Shivan force to be at the end of FS2, it seems improbable that if Lucifers are a main weapon in the Shivan armada, they'd have one stuck out in no-Shivans-land beyond Ross-128.
Yet, the Shivans have demonstrated that they won't commit Sathani to attacks unless it is absolutely necessary. In FS2, they don't make any moves with SJ1 until a Ravana is annihilated, and the upstart Terrans and Vasudans continue to intrude into the nebula.
This is therefore my picture of the Ancient/Shivan war:
An Ancient expeditionary force is travelling through space, setting up Knossos devices, and travelling through them. After opening one device, they discover a strange group of red-black ships (my view is Rakshashas or Cains). Being the greedy Ancients they are, they open fire, damaging or destroying some of the ships. Feeling confident they will win, they call in their Ancient buddies, to slaughter this new race. The Ancient extermination force arrives, and they head through the nodes in this new sector, hunting Shivans,
However, the Shivans are not going to let the Ancients beat them, and thus call in their own reinforcements - a couple of Lucifers and Ravanas, and Demons. The two fleets one system away from the initial encounter. The Demons, and a couple of Ravanas bite the dust, but the Lucifers spearhead a counterattack, driving the Ancients out of the node. Togeather with wings of Dragons and Maras, the Lucifers keep the Ancients running, backtracking them through the Knossos devices, using their ability to travel through unstable/small (See Petrarch's desription of the plan to seal Capella if you have questions about this) nodes to counteract the Knossos shutdowns. The Ancient expeditionary force had called home to let them know trouble is coming, and the Ancient fleet rallies on the entrance to an important system to mount a defense (much as the GTVA fleet rallied to try to stop SJ1.)
When the nearly ruined expeditionary force arrives in the system, the Ancients feel a bit of fear, as they see how badly the force had been mauled. Then the Shivans arrive, and a titanic disaster starts begins. The ancients can eventually wear down the shields, destroying a significant portion of the fighter force, but focusing their weapons on the Lucifers to take down the shields takes too long to do much damage (possibly one or two go down, but at the cost of more than half of the Ancient's fleet). Now, the Shivans pursue the fleeing ancients into their other systems, by following the Knossos trails. But, they also start adding Sathani to the mix - the Lucifers keep the Ancients occupied, while one or two Sathani hang back, blasting ships out of space at a fast rate.
Finally, the Shivans come to the Ancient homeworld. Here, they are frustrated by the futile defense attempts of the Ancients, and decide to nuke them. So, they use their Star-nuker gun, and fry the system. Then they head out to the other systems, to wipe out the leftover ancients the fun way. Leaving a swirling cloud of gas marking the final resting place of a great empire.
With their fleets, shipyards and homeworld gone, the last few ancient bases huddle silently, nervously watching the void of space for the arrival of the destroyers. One by one the bases are destroyed. Until only one remains, in a system later called Altair. Here, flights of Seraphim and Maras cut down out of the skies, killing the ancients in a matter of minutes, and then departing, leaving ruins - and the key to the Shivan's weakness buried beneath rubble.
Thousands of years later, a shivan commander left as a guardian over the back end of the ancient's systems (also known as GTVA space), has his souts report that two new space-faring races are emerging. He takes matters into his own hands, and prepares his fleet, driving his Lucifer into the GTVA systems, wrecking anything that comes against him, until Vasudan scientists uncover the ruined base on Altair. There, the GTVA find the key to stopping his Lucifer, and ambush it in the Sol node. The rest of his force is hunted down and destroyed.
32 years later, Bosch deploys Roemig and the Trinity to open the Ancient's closed node. The Shivans, wondering what they garrison commander was doing coming home, send over some fighters and a transport to talk to him, only to find a Fenris. They fight, but not expecting hostiles, the Shivans are beaten back. The ambassador goes to Shivan command, and notifies them that a new race has arrived in the Ancient's home system.
What follows is the Second Shivan war, in which the Shivans decide that to destroy this troublesome sector of space they need to go from star to star, annihilating it. However, the Bastion and Neried smash the nodes, sealing off the main route from the Shivan systems and the GTVA ones. Or so it is thought.