A subpotentate was one of the ten rulers of the ten governing districts or "kingdoms" of the Global Community. They were originally called ambassadors when Nicolae Carpathia chose them as part of the security council. They fulfill Scriptural prophecy speaking about ten kings, represented by the ten horns of the Beast in Revelation 17:12-14, who were given power to rule as kings with the Beast for "one hour".
Only three of them, Rehoboth, Od Gustav, and Enoch Litwala, are directly mentioned by name, but they are occasionally with Carpathia as he comes up with ideas for the world, such as imposing taxes on certain areas. It is mentioned in Soul Harvest that the one for the United North American States is a former United States senator from Texas.
In "The Indwelling", three of the subpotentates, including Enoch Litwala, would be killed by Leon Fortunato by his calling down fire from the sky at the memorial service for Nicolae Carpathia, where he would be visibly resurrected.