After ten thousand years of cullings by the Wraith, the Brotherhood that guarded the Potentia were wiped out of existence. Today, the Sudarians are all but extinct. The planet's present inhabitants, the Daganians, are only at a Renaissance level of development.
It is not clear if the Sudarians are the direct ancestors of the Daganians, or if they are a culture that arrived on Sudaria, renamed it Dagan, and embraced the planet's ancient history.
The Brotherhood - Allina helps the Atlantis expedition sift through countless historical documents in the hopes of uncovering the coordinates of the Potentia.