The High Evolutionaries are powerful entities attuned to the cosmos. They reside either within the Matrix or can be contacted there. They possess a council, who will sometimes take action against great cataclysms.
Members include:
- Rassilon
- Merlin the Wise
- Dakon Theka
- Thane of Kordor
- Morvane
- Bedevere
- Demoiselle Drin (replacing Merlin)
The Doctor first contacted them when the demon Melancius broke free and caused time distortions. The Evolutionaries informed him of the threat. (DWM: The Tides of Time)
The Evolutionaries would hire the Treshold to try and prevent the Daleks from invading parallel universes. (DWM: Fire and Brimstone, Wormwood)
The Doctor's mind would be summoned to them when he was hospitalised on Gallifrey. They warned him of a vision of Gallifrey turned into a violent empire. By this point, Merlin had been replaced by Demoiselle Drin of the Order of the Black Sun. (DWM: The Final Chapter)
Paul Cornell's comic Captain Britain And MI:13 mentioned in #2 that "the Higher Evolutionaries of all the worlds" have imprisoned Merlin in a realm of dark magic; Merlin here was shown to be the Doctor Who Magazine Merlin, already established by Marvel Comics to be a guise of their Merlin.