2165-2170: Citadel Council-The Newcomers
First Contact for the peoples of the Citadel Council races were actually more common than most people of its respective nations believed; a new sentient species was found at least once a century. Most, however, were extremely primitive societies, and were left alone, with protection from any who wished to exploit them. Only on very rare occasions, a race was discovered that had entered an industrial age, and cautious attempts were made to communicate with them. The last time this had occurred was with the species that called itself Yahg, and their massacring of the Council's initial diplomats had left a foul taste in the mouths of all who remembered the event.
For them to encounter a race that had developed interstellar capabilities, and had already staked its claim on a small slice of the galaxy, so soon after this blundered meeting, was panic striking.
Benezia, Matriarch of the asari, had been traveling to a diplomatic meeting with the Batarian Hegemony, in an effort to coordinate an effective resistance against the gangs of slavers that had been attacking outlying colonies of multiple species. Everyone on the ships knew that the mission was pointless; few people would say it out loud for fear of backlash from the extremely egocentric Hegemony, but it was common knowledge to all that the Batarian government itself was the driving force behind these raids. Not intending to waste time on the matter, the diplomat ship and its escorts decided to use a secondary mass relay to a nearby relay cluster that had recently been discovered. All of the relays at the intersection, baring the two larger primary ones, had been activated, but regular routes had not been established as of yet; the delegation expected no traffic of any significance.
What they found instead was a flotilla of System's Alliance ships, which had already activated one primary relay, and were beginning to do the same with the second.
Upon spotting the asari ships, the humans immediately ceased their activities, and fled back beyond the newly active primary relay to their home territory. Benezia and her followers were now faced with a choice that could have disastrous consequences; should they alert the Turian fleets that the activation of prime relay, a grave offense in Citadel Space, had occurred, or should they follow the new race, that clearly did not know the dangers of such a practice, and make contact themselves.
The Matriarch settled on the second option. And the rest is history.
Of all the races of the Council, the asari were easily the most ecstatic at the meeting with humanity. In addition to the obvious physical similarities, the Alliance and the Republics shared numerous cultural ideals; both were democratic societies with heavy emphasis on the rights of individuals, more inclined to seek diplomatic solutions than armed conflict, and eagerly embrace the cultures and ideas of others. In the opening days of humanity's assimilation into Citadel Space, many believed that asari and humans were, in fact, descended from the same species, and had been artificially separated to different planets by the Protheans, or another older space faring race. This rumor would continue for decades, in spite of overwhelming evidence to the contrary.
The Turian Hierarchy was less thrilled with the Alliance, mainly due to their habit of opening deactivated primary Mass Relays, a practice that had been banned in Council Space for two millennia after the Rachni Wars had nearly destroyed the civilization. As such, the peacekeeping military was appalled that the Alliance would do such a thing. Fortunately, upon learning of the ancient war, the Alliance was appalled by its own lack of caution, issued a public apology for their actions, and promised that it would cease opening primary relays it encountered. Satisfied, the Hierarchy began its own study of the Alliance, particularly the peoples' past military exploits. Turian generals were particularly awed by humanity's amphibious invasions; Turians are unable to swim for any extended period of time, and so have always steered clear of ocean warfare. As a result, the Normandy invasion of World War 2 quickly reached legendary status amongst Hierarchy populous, and one admiral declared the United States of America's island-hopping strategy in the Pacific Ocean "more of a story out of mythology than a military campaign".
The Salarian Union had some of most pressing interests in the Alliance joining Citidel Space; of all the major powers, the Union shared the longest physical border with human space, and were concerned that this would leave them venerable to attack. The concern was not of an attack by humans, as the Alliance fleet, only numbering 3 fighter carriers, 20 cruisers, 40 destroyers, and 60 frigates, was vastly outnumbered by the Salarian fleet and that was without taking the technological differences into account, but rather that an concentrated attack from a united Terminus would smash through the weak nation, and move on to Salarian space. Thus, the Union signed a treaty with the Alliance that guarantied military assistance in case of attack and assistance with technological advancement, in exchange for several recently discovered garden worlds near human space. The deal was accepted with near universal approval from humanity's Parliament.
The associate species reaction was mixed. While they were almost all cautiously optimistic about the arrangement, some were less so than others. All recognized that with a new species came more competition to attain a seat for their people on the Council.
The hanar, at first, were apathetic to the new comers; their government, the Illuminated Primacy, had long since been an isolationist state, with only a few trade relations with other species. That changed, however, when humanity dropped a proverbial bomb; deep in the Prothean Archives on Mars, explorers found a stone slab, carved in the likeness of the base's original owners; humans were the first race to find a confirmed likeness of the Protheans, who the hanar worshiped as their gods, calling them Enkindlers. As a result, the Primacy immediately set up diplomatic relations with the Alliance far in excess of any other species, and problems immediately arose as millions of hanar attempted to enter the Sol system to see the faces of the divine beings themselves.
The Elcor, after initial curiosity in the new members of the Citadel, largely lost interest in the Alliance; human and elcor space were on opposite ends of the galaxy controlled by Council members, and both were too weak to bridge the colossal gap easily. The Elcor Courts of Dekuuna and the Systems Alliance maintain diplomatic relations, but have very little to talk about; there is neither a conflict nor concurrence of interests.
The Vol Protectorate, while technically part of the Turian Hierarchy, nevertheless have a large amount of independence in economic matters. Having evolved as a mercantile people, they had, over time acquired a keenly honed business sense, and this came in full swing upon establishing contact with the newfound humans. Almost immediately, Volus merchants began exchanging technology for human-unique items, such as medigel, though this technology was outdated by decades. Although many Council species decried this practice as blatant profiteering, the human customers were ecstatic; though uselessly old by Volus standards, the tech provided was incomprehensibly advanced to humanity, and reverse engineering these items speed up the Alliance's tech advances by decades.
The Batarian Hegemony is considered, by far, the most antagonistic in the regards to humanity's arrival. The species had long believed itself intellectually superior, due to them having four eyes while most other species possessed only two, and generally viewed the Alliance as yet another race of inferiors that would be subjugated once the Hegemony inevitably took its rightful place as the masters of the Milkey Way. When the Alliance's existence was first announced to the Council by Matriarch Benezia, the Hegemony's first act was to covertly commission a slave raid on the human world of Shanxi, in an attempt to subjugate the humans and ensure a new, exotic element in its slave trade. Fortunately, the slaver armada was intercepted by the turian 31st Fleet, on its way to the 314 relay with the specific intent of preventing such an attack, and the turians surrounded the unprepared criminals and annihilated them to a man. With their initial plans foiled, the Hegemony grudgingly sent diplomats to join with the assembly of species at the Citadel to greet the Alliance ambassadors.
In order to ensure smooth negotiations with the Alliance, the slaver raid, and the existence of the Batarian slave system, were not mentioned.