The Sentient Milieu was an association of starfaring races that existed 25,000 years ago. It was formed over the course of several thousand years to "mutually enrich their respective cultures, to provide a safe creche for emerging sentient species and to afford themselves a degree of protection from external hostilities via military alliance," as the Melnorme put it.
The seven major members of the Sentient Milieu were
- the Drall, one of the four founding members
- the Faz, joining about 22,000 years ago
- the Mael-Num, one of the four founding members
- the Taalo
- the Ur-Quan (still one race at that time), the last major race to join
- the Yuli
- the Yuptar
The Milieu incorporated at least five other races: at one point, the Melnorme refer to the "the remaining eleven races of the Milieu," a count which is known to not include the Taalo and may also exclude other major Milieu members.
None of these unnamed others are likely to have played a large role. The Ur-Quan Kzer-Za refer to the "six races of the Sentient Milieu" and the Ur-Quan Kohr-Ah plainly refer to "all six of the other races in the milieu". There are no known references to specific additional Milieu members.
The end of the Sentient Milieu as an organization was brought about with the advent of the Dnyarri.