Events concerning Thessia and by proximity Illium during the war are collected here.
May 15: Illium
A direct threat to Illium was foreshadowed by the loss of contact with Talik and Vantage, neighbouring systems projected to be avenues of approach for an invasion of Tasale. Illium’s ruling Board of Governors made no formal statement concerning the Reapers - the nature and extent of their forces still being uncertain at this early stage of the war - but enacted a range of emergency measures, including placing the Nos Astra Exchange under a temporary freeze to halt panic selling, and entering talks with several private corporations in possession of military assets. Several days later, Reapers transited the Tasale relay and advanced on Illium. The Board judged the Reaper vessels’ threat too great to permit safe departure from the system, and ordered all civilian vessels grounded. Elements of Illium’s Tasale Fleet engaged the oncoming Reapers - identified as Destroyer types and lighter units only - while the major cities projected as Reaper landing sites commenced evacuation. Tasale Fleet’s strength was insufficient to halt the advance, and some Reaper vessels breached the defensive line and began surface attacks. However, despite significant damage and loss of life at some evacuation points, much of the population under threat were able to be moved to secure locations. Meanwhile, Tasale Fleet enacted the Board’s contingency plan, abandoning attacks against Reaper warships in favour of precision WMD strikes against troop carriers. Although Fleet losses were high, the strategy succeeded in denying the Reapers the immediately available ground forces necessary to rapidly expand from their bridgeheads.
Illium Under Siege
With a number of major cities, including Nos Astra, now in Reaper possession, but the ground advance blunted, those areas to which populations had been evacuated were able to shore up their defences. Many smaller settlements fell under attack from orbit, and were quickly abandoned amid catastrophic losses, but the largest secure cities managed to mount sufficient anti-air and anti-orbit defences. Reaper ground forces consolidated their positions and began rebuilding the forces diminished by their troopship losses, scouring all contested areas of the planet for victims to convert to husks, and launching periodic raids against the remaining cities. Nos Varda - a satellite city to Nos Astra, and the destination of its evacuees - became the de facto planetary capital during the siege, protected by heavy defensive installations, barrier projectors, and a combined force of Illium huntress cadres and forces of the Eclipse mercenary consortium, which accepted effective nationalisation for the duration of the war in exchange for lucrative concessions. Although Reaper forces based in nearby Nos Astra mounted constant small-scale probing attacks, and several large assaults (including one later dubbed the 'Battle of Nos Varda', which succeeded in breaching the city's barrier lines, threatened key military installations, and inflicted significant civilian casualties before being repulsed), comprehensive scouting and sabotage operations conducted by huntress/Eclipse forces prevented the Reapers from amassing sufficient husk forces to overwhelm the city.
In addition to seeing to its own survival, the Nos Varda Provisional Authority, formed from the survivors of the Board, took a supervisory role among the remaining cities, coordinating system defence and prioritising incoming resources. Surviving units of Tasale Fleet concentrated on harassing Reaper vessels wherever possible without incurring prohibitive losses, emplacing stealthed FTL communications buoys to periodically replace those detected and destroyed by Reapers, and providing escorts and diversionary attacks to allow supply convoys to enter the system and reach Illium's cities. Despite the deadly nature of the Reaper assault on Illium, strategists analysing their behaviour concluded largely unanimously that their primary goal was simply to halt commercial activity in the system, thereby destabilising the Terminus Systems economy in general. So long as this goal was achieved - which it was for the duration of the war - the capture and/or destruction of Illium’s population appeared to be a secondary priority, pursued only as and when the forces already present in the system could muster sufficient offensive momentum without requiring reinforcements from Reapers already committed elsewhere.
Cerberus Coup Response
The Republics only became seriously involved in the war effort after the attempted Cerberus coup on the Citadel. In a joint statement by Xevan Chiota and Malkis Oarian, Press Secretaries for Councilors Valern and Tevos, the Citadel Council stated that “We have seen many atrocities during this war and, while Cerberus’ actions are despicable, we must work together to defeat the Reapers. Now, more than ever, we need soldiers to help defend the many colonies throughout the galaxy who face imminent attack by Reaper forces.”
To quote Commander Mark Wallace (N7):
"The ramifications of the assault are huge, most of them good. Dominic Osoba is better than Udina, the asari and salarians are providing a token amount of military aid while their prominent members are seriously considering further aid and more people care about the fact that there are docking bays full of refugees and that we are losing contact with entire systems. In the grand scheme of things, the attack on the Citadel will probably do more to help us than hurt us in the war".
The Council subsequently created the Citadel Defense Force to support Shepard in the war against the Reapers. The CDF included ships and soldiers from every Council race. Complements from a few species without official membership status also quietly joined. After the attempted coup, no offer of assistance was being turned away by the Council and its advisors.
Nevos was hit by the Reapers around the same time as Dekuuna came under fire. Being a relatively unimportant word in terms of industrial resources, the Reaper attacks concentrated on the almost defenceless spaceport facility near the capital of Astella. The destruction there was extensive but the Reapers didn’t come to stay, as their forces moved on to the more important targets of Dekuuna and (especially) Hyetiana and Cyone.
The coordinated Council forces, though, were making progress in some areas. It became easier for people to travel through asari space to join family and friends on Thessia. The Citadel’s security improved as a result of the number of refugees leaving the station.
July 10: Thessia Invaded
The asari homeworld now came under direct attack.
While other species met the Reapers head-on, the asari resorted to dangerous hit-and-run tactics to harass their attackers. By engaging in guerilla strategies - blast a Reaper ship, then jump to FTL where they couldn’t be tracked - the asari forced the Reapers to remain on the defensive. Unfortunately, the Reapers’ greater numbers allowed them to accept certain losses, so they soon ignored the attacks against them and began orbital bombardment of Thessia. This in turn forced the asari to defend their homeworld with a more traditional stance, facing the Reaper forces directly. As soon as the Reapers landed on Thessia, the harvesting began.
Following a tip-off by the desperate asari councilor, Shepard and her team travelled to the besieged planet in search of an artifact that could help with the Crucible project. Shepard's team arrived at the temple of Athame to find a security field blocking the entrance, strangely high-security for a worship house of a dead religion. When T’Soni deactivated it, they entered the temple and found the scientists dead, but not at Reaper hands. They searched the building, which housed artifacts related to worship of Athame - including several that looked suspiciously Prothean. While T’Soni explained the temple’s history, Shepard came to a realisation; the artifact the Councillor sent them to find was a Prothean Beacon hidden within the temple. Considering the building’s age, the beacon was likely the reason why the asari were technologically and scientifically ahead of the other races, and they’d directly violated their own Council law by keeping the beacon to themselves. The beacon powered up upon detection of one with Prothean-like brain patterns (which Shepard received in the form of the Cipher) and once the squad fully activated it, a Prothean VI identifying itself as Vendetta appeared. Establishing that it was in a post-Prothean cycle and detecting nearby Reaper forces, it attempted to shut down, but Shepard insisted that it wait and provide information on the Catalyst and Crucible.
Vendetta explained that the Crucible was not of Prothean origin, but was a cumulative design spanning countless galactic cycles stretching back millions of years. The Protheans themselves never used it because their efforts were sabotaged by a splinter faction who (like Cerberus in the present cycle) argued the Protheans should control the Reapers, not destroy them. By the time it was discovered the separatists were indoctrinated, it was too late; the Prothean order of battle was too fractured to coordinate an effort to activate the weapon. Vendetta also mentioned that the Protheans had learned of similar patterns of evolution and dissolution occurring in every galactic cycle, with each path of advancement and conflict happening differently but in fundamentally similar ways - too similar to be merely chance. Vendetta inferred that the Reapers were “servants” of the pattern, not its creator, but couldn’t identity their true master or motive, only their intention: galactic annihilation. Before Vendetta could specify what the Catalyst was, it detected an indoctrinated presence nearby and shut down.
The intruder was Kai Leng, who demanded their attention, pulling a drone from his coat and remarking that “Someone would like to talk with you”. The drone projected a hologram of the Illusive Man, who had learnt of the Thessia beacon from the Mars Archive and mocked T’Soni for missing it. He went on to expand on his beliefs and attempted to convince Shepard that controlling the Reapers was the best course of action - and that the Thessia beacon contained the information needed to do so. Shepard asserted her conviction to destroy the Reapers, and dismissed the Illusive Man’s scheme, accusing him of being indoctrinated. Rebuffed, the Illusive Man ordered Leng to kill Shepard and recover the data.
The Normandy’s communication specialist, Samantha Traynor, mentioned that she had traced the route taken by Leng’s shuttle as it fled Thessia, as far as the Iera System. She had lost it there because the signal was being actively blocked. Despite the fact that the only thing of note in that system was Sanctuary, a refugee camp on the planet Horizon for those fleeing the war, the Commander decided that a lead was still a lead, no matter how slim, and agreed to check it out.
Within hours, nearly all communications with Thessia were severed, leaving the fate of billions of asari uncertain. The fall of the Crown Jewel of the Galaxy came as a critical blow against the Republics, who had been contributing forces to Alliance efforts across the galaxy since Cerberus’ attempted takeover of the Citadel the previous month.
The loss of communication between the planet and the Citadel was confirmed by Councilor Tevos in a press conference at 8:42 GST. "We don't have any information behind this blackout at this time," Tevos reported to a subdued press corp, "but with the recent attacks occurring elsewhere in the galaxy, we can only assume the worst. However, we must keep hope alive. We are a long-lived and wise people, and have some of the most trained warriors in the universe. I have no doubt our people will weather this storm. If anything, this simply hammers home the point that we must find an end to the Reaper menace, and fast".
On Thessia, the destruction of communications networks, in combination with Reaper attacks aimed directly at killing as many leading Matriarchs as possible, resulted in the total collapse of global government. A loose coalition of huntress and commando units who survived the initial invasion, along with civilian militias, were able to facilitate communication and coordination between geographical regions, but decision-making outside of military matters was left in the hands of whatever local civilian leaders arose.