The Krogan Rebellions were a major conflict between the krogan and the Citadel Council that began in 700 CE and continued for decades. The Rebellions were preceded by over three hundred years of aggressive krogan expansion coupled with booming population growth. Tensions came to a head when the krogan remorselessly advanced onto worlds already claimed by other races. With the krogan unwilling to back down despite Council demands, the Rebellions ensued.
The Rebellions[]
Unchecked Expansion[]
The causes of the Rebellions stemmed from concessions the Citadel Council made to the krogan in gratitude for their service in the Rachni Wars. The krogan were given the conquered rachni planets along with several pristine, habitable worlds. However, due to the harsh conditions of their homeworld Tuchanka, krogan birth rates were quite high in order to sustain their numbers. When they spread to other planets, their naturally swift breeding cycle and lack of sufficient predators resulted in the krogan spreading throughout the galaxy like a plague.
The Council became concerned as the krogan began to annex territory from other Citadel races. The krogan became more aggressive as other races tried to protect their worlds, until the krogan attempted to settle the asari colony of Lusia. When told by the Council to leave, the krogan refused. Their representative, Overlord Kredak, stormed out of the Council chambers, daring them to take their worlds back. War broke out afterward.
Facing the Spectres[]
The Council had taken precautions. The finest STG operators and asari huntresses had been drafted into a covert "observation force", the Office of Special Tactics and Reconnaissance. The Spectres opened the war with crippling strategic strikes. Krogan planets went dark as computer viruses flooded the extranet. Sabotaged antimatter refineries disappeared in blue-white annihilation. Headquarters stations shattered into orbit-clogging debris, rammed by pre-placed suicide freighters. Unlike the Citadel races, however, the krogan could replenish their numbers very easily and a krogan victory began to seem inevitable.
Finally the Council turned to the turians, newcomers on the Citadel who had a massive fleet and a militaristic culture. Establishing hidden command centres, like Pinnacle Station, turians were able to defeat many krogan bands. But the krogan responded with characteristically horrific attacks on turian worlds, using asteroids as weapons and rendering three planets totally uninhabitable.
Unfortunately, this was exactly the wrong approach to take with the turians. Turian military doctrine was (and remains) not simply to defeat an enemy, but stop them from ever becoming a threat again. Far from turning turian public opinion against the war, the ferocity of the krogan only served to stiffen their enemy's resolve and unite every turian against them.
The Genophage[]
Seeing that the krogan did not generally surrender upon a defeat, and understanding the krogan could effectively call upon limitless reinforcements, the turians contacted the salarians, who had engineered a powerful bio-weapon called the genophage. This was intended to produce a genetic mutation in krogan that could result in only one in one thousand krogan births being a success.
The salarians had never intended to use the genophage and planned to use it as a deterrent. But the salarians and turians had very different philosophies on warfare. Once the turians received the genophage, they almost immediately deployed it in 710 CE, and krogan numbers began to dwindle. Coupled with a renewed military push from the turians, the krogan soon realised their position was hopeless. Without hundreds of krogan offspring being produced at one time, they could not hope to stand against the turians. A female krogan warlord, Shiagur, actually used her rare fertility to draw the strongest males to her band, but even she couldn't hold out against turian peacekeeping forces, who finally killed her at the Battle of Canrum. In retaliation, many of the turians responsible were hunted down and killed by vengeful krogan males. Canrum was the last krogan push before the Rebellions ended.
Finally, besieged on all sides and knowing the survival of their species was at stake, the krogan surrendered. That was not the end of hostilities, as many rogue warlord and insurgents refused to surrender, and had to be wiped out by turian task forces. Some even vanished into frontier systems to become pirates.
For their role in quelling the Krogan Rebellions, the turians were rewarded with a seat on the Citadel Council.
Legacy[]
The krogan are deeply bitter about the outcome of the Rebellions. As Wrex puts it, "to thank us for wiping out the rachni they neutered us all." In the aftermath of the Rebellions, there was a movement on the Citadel to have the Krogan Monument removed from the Presidium, but the Council refused. The Rebellions didn't change the fact that the krogan had destroyed a galactic menace during the Rachni Wars, though they had become a menace in turn.
In 2185 CE, a mass grave of some 430 turian soldiers who fought in the Krogan Rebellions was found on the planet Uresium. The grave site had been covered over by local flora until seismic activity in the area re-exposed it. Turian authorities, with the help of Uresium colonists, set about unearthing the remains for transport to Palaven for a proper burial.