High Galactic War

The first major galactic scale conflict in the Milky Way Galaxy, the war was a massive, and highly destructive event, which claimed the lives of millions. It was actually a complicated series of orchestrated events by the Zinroth Imperium to weaken the galactic infrastructure in preparation for their invasion. While it did successfully wage for nearly four years, the zinroth attacked prematurely, before the governments were weakened enough. Due to the sudden appearance of a mutual enemy, a ceasefire was declared.

Arrival of the Zinroth
The war's origins can be traced all the way back to the appearance of the first zinroth vessel into the Milky Way through a wormhole. The first race they entered contact with were the vorcha, and after failing to subjugate them, the zinroth elevated them, allowing the vorcha to establish themselves as a great power. With a monumental shift in the balance of galactic power, the Citadel governments became anxious. Distrust began to take root, giving the zinroth the opportunity they needed.

Citadel Incident
Though the races were nervous about the vorcha's rapid rise in power, and its continued rise, they failed to fully descend in outright accusation. Growing impatient, the zinroth made their move. Convincing the vorcha Dominar to bring an asari delegation to Omega, the vorcha center of military operations, zinroth agents composed an infiltration. They had the Destiny Ascension requested directly by the vorcha government, and the asari government, not inclined to potentially antagonize the Vorcha Dominion, agreed.

After the ship arrived at Omega, accompanied by a sizable asari fleet (the vorcha refused to allow any turian vessels into their space), the delegation was brought aboard. There, they were prestened with a sphere of supposed vorcha design, as a peace offering. Though the asari were suspicious (the vorcha were not known for being particularly aesthetically minded), they accepted the gift. The gift was brought back to the Citadel, and presented to the Council, who accepted it with open arms, hoping to normalize tense relations with the vorcha.

However, the true intentions of the sphere alluded them. It was, in fact, a zinroth device, designed to transport zinroth agents, without hosts, to a designated area, where they could possess influential figures. Instead of going for the Council, the agents left the sphere while in the Destiny Ascension. Dozens of parasites slithered through the ship, managing to gain access to multiple asari. However, not anticipating asari biotics, subjugating the asari proved more difficult than they had assumed. Despite these setbacks, the zinroth still managed to establish a level of influence over the asari, and managed to gain access to several key positions, including the bridge, and security system.

Not long after, a summit set by the Citadel was held. High ranking officials came from all over the galaxy, ranging from the Krogan Emperor, to the Quarian Grand Councilor. Seizing the opportunity, the zinroth aboard the Destiny Ascension looked for an opening. When Primarch Victus of the Turian Hierarchy arrived on his ship, the last one to arrive, the zinroth acted. They managed to assert enough control over the asari to fire on the primarch's ship, destroying it completely, and killing the primarch. The zinroth then quickly evacuated their hosts, and took shelter back in the sphere, but before intricately altering the ship's logs and video systems.

War Declared
The turians, understandably outraged, demanded retribution. The position of primarch fell to the Garrus Vakarian, and he demanded that the asari surrender the crew of the Destiny Ascension, as well as the ship itself. However, due to altering of ship logs by the zinroth, the asari interpreted the primarch's ship as making an attack move against their vessel, and they refused. The turians responded by withdrawing their councilor, and declaring war soon after.

Division of Sides
Initially the war between the turians and the asari was relatively restrained, with other governments reluctant to participate in such a conflict. Dissatisfied with this, the zinroth took it a step further. They located a group of salarian extremists, who were adamantly anti-krogan, and just needed a slight push. The zinroth took them host, and easily convinced them to act.

Assassination of Krogan Ambassador
While the turians had left the Citadel, most races still operated in it (the turians and the asari agreed at the very least to not involve the Citadel in the conflict). However, this did not stop conflict from arising; the Krogan Empire was vocal in their support for the Turian Hierarchy, as was the Quarian Confederacy. They accused the humans and salarians of bias, and said that without the turian involvement, the Reaper War would have been lost.

Taking advantage of this, the zinroth concocted a plan with the extremists they now influenced. They had a bomb planted near the krogan embassay, and detonated it, killing the ambassador, and several other officials. With what was considered to be hard evidence pertaining to the salarians, Emperor Wrex demanded compensation. The salrians however, figuring it to be another krogan ploy to gain sympathy, refused. The asari, wanting salarian technology and intelligence, did not involve themselves in the conflict. The krogan walked out on the Council, and the Krogan Empire declared war on the Salarian Union. Out of respect for their long time friends, the Quarian Confederacy sided with the krogan and the turians, forming the Grand Pact. The salarians stood with the asari against the krogan, and with that, the High Galactic War had begun.

Citadel Alliance
Though the asari and the salarians had superior technology, they both knew that on a large scale conflict, they would be defeated by the superior military forces of their enemies. Aware of this, they took drastic measures. They made an appeal to the Vorcha Dominion for support in the war; initially Dominar Gryll balked at the notion, but he later agreed after speaking with the zinroth. The vorcha then agreed to an alliance with the Asari Republic and the Salarian Union, though the terms of the alliance were steep. Both sides were to give vorcha completely free reign of the galaxy, and access to the resources and technology they required. Aware of the results of refusing, the asari and salarians agreed. The vorcha soon joined the conflict, resulting the formation of the Citadel Alliance.

League of Neutrality
With the great galactic powers quickly dissolving into large scale conflict, the remaining races were caught between a rock and a hard place. None of them wanted to deal with a ware that could prove incredibly destructive, but they all knew that if they stood completely alone, they would be swallowed. TO this end, the elcor and the hanar formed the League of Neutrality, departing from the Citadel, and establishing a base in space both governments shared. The Batarian Hegemony, still reeling from there devastating defeat at the hands of the vorcha, also joined the League.

One race that many were very aware of, were the rachni. After the wars, the rachni had been given a consulate on the Citadel, where the interests of their people could be expressed. Both the Grand Pact and the Citadel Alliance appealed for rachni support, but the rachni, not wanting to be dragged into another massive conflict, instead entered into the League of Neutrality.

Humans Join
The humans, wanting to keep their focus on rebuilding their infrastructure, wanted nothing to do with such a conflict. Originally, they intended on join the League of Neutrality, so that they would not be dragged into the conflict. However, after the vorcha joined the Citadel Alliance, the humans were suddenly much less inclined to allow the possibility of letting the vorcha get free reign of the galaxy. Fearing that the vorcha could take advantage of humanity's weakness, and launch an invasion of their space, they sought to be protected. So instead of joined the League of Neutrality, they petitioned for joining the Grand Pact, hoping to be able to get the turians and krogan on their side. They were quickly accepted into the Pact.

Early Process of the War
For the most part, the war was at a relative stalemate. With the Citadel forces boosted by vorcha military power, it was becoming fairly clear to the Pact that they were not going to win the war as easily as initially anticipated. Initially the battles were kept to small skirmishes between forces, since not many races had the desire to enter a large scale battle involving possible planetary invasion. This came to a close with the invasion of Citadel forces into Tuchanka. However, their forces were crushed, and they were forced to retreat.

WIth the Citadel taking the first step in large battles, the Pact began to become more daring. They began raiding planets under their jurisdiction, and the Citadel did the like against the Pact. The war became increasingly bloodier, with ships being shot on sight.

Invasion of Thessia
After slightly more than a year of extended conflict, the war swung back into the favor of the Grand Pact, with an invasion of Thessia by a combined krogan, turian, quarian, and human fleet. Though they suffered lossess, Thessia was successfully taken, and occupied. The Citadel Alliance's center retreated to Sur'Kesh, and the asari Grand Secretary escaped, keeping the asari center of government intact, but the fall of their homeworld, demoralized the asari forces.

With Thessia under the control of the Pact, the Alliance had lost much of its centralization. The remainder of asari forces fled to Sur'Kesh, where a base was established. Thessia fell under occupation of primarily krogan forces, with some krogan going so far as to proclaim Thessia as a part of the Krogan Empire. The asari, once conisdered the most powerful race in the galaxy, were exiled from their homeplanet, and those that remained were in the shadow of the krogan.

Weaponization of Omega
While the asari demanded a fleet be formed to retake Thessia, the salarains and vorcha were hesitant to commit their forces to take the planet. The vorcha had, instead, committed their resources towards the full weaponization of the Omega station, hoping to convert into a completely functional, mobile battle station.

When word of this got to the asari and the salarians, they also contributed their resources, hoping to use it in the retaking of Thessia. However, geth agents who managed to snatch transmissions got wind of this as well, and relayed the information back to the Pact. Fleets were launched at Omega to inhibit the progress, but they were beaten back repeatedly by Citadel forces.