Mass Effect: Blackwell

The volus government is known as the Vol Protectorate. Rather than being a fully sovereign government in its own right, the Protectorate is a client state of the Turian Hierarchy. In return for falling under the protective umbrella of the turian military, the volus pay a tax to the Hierarchy, as well as deferring to the turians in all foreign policy matters and providing auxiliary troops to the turian armed forces. They still maintain an embassy on the Citadel, making them a member species of the Council.