Tension had grown between the cherov and quarians after a group a cherovs attacked a quarian who had been on Pilgrimage. The cherov government claimed that the quarian was a threat to their species' well-being. The quarians then requested assistance from the Citadel Council. They were denied because the cherovs' government was located in the Terminus Systems. After they were denied, the Alliance military sent a group of soldiers to assist.
- Mass Effect: The Quarian Wars (First appearance)