The Sovereign Seven were a group of aliens from various planets exiled to Earth, where they battled various villains, most notably the Female Furies of Apokolips. On Earth, they made their home at the Crossroads Inn, owned by Pansy Smith and Violet Jones. The original group consisted of Cascade, Finale, Rampart, Reflex, Indigo, Network, and Cruiser; later Rampart was killed and then replaced by Power Girl.
The main characters of Sovereign Seven were all gathered by Cascade as a mysterious force known as The Rapture destroyed their home worlds. Each of the Sovereigns was of royal heritage among their people. Cascade is the daughter of Maitresse, who's power is on the scale of Darkseid (with whom she seems to be friends).