The Rachni Wars

A conflict that started around 1 CE between the early Council and the Rachni. It started when the early Council was exploring the mass effect relay system and stumbled into Rachni territory; however, the territorial nature of the Rachni led to them attacking the Council explorers and starting a war against the Council. The conflict went on for centuries as the Rachni had overwhelming numbers and slowly invaded Council territory. The Coucnil was clearly going to lose the war until the Salarians, conveniently, found the Krogan and "uplifted" their culture. With the Krogan soldiers on their side and ability to match the Rachni's survival abilities in severe conditions, the Council was able to push back the Rachni and wipe them out. This was seen as the only course of action to take since the Rachni Queens were unwilling to communicate or negotiate during the war. The Rachni were declared extinct by the year 300 CE and the Krogan became heroes of the galaxy, but this was a fleeting victory for the Council in the end. This war also led to the creation of the law against exploring the mass effect relay system at a rapid pace (to prevent mass interstellar conflicts) that later led to the Turians attacking human explorers and starting The First Contact War.