A Regent was a form of monarch. They were usually selected to administer a State because the ruler was a minor or was not present or incapacitated.
Two Regencies were...
- Princess Wensicia became Regent of House Corrino, upon the death of Shaddam Corrino IV, after Paul Atreides took the Golden Lion Throne. In this case, Wensiscia became regent since her oldest sister, Irulan Corrino had been absorbed into the Atreides Household.
- Alia Atreides became Regent of House Atreides and the Atreides Empire after her brother Paul Atreides walked into the desert, 12 years after he ascended to the Golden Lion Throne. Alia became regent for Paul's children, as Leto Atreides II and Ghanima Atreides were still minors when Paul walked into the desert.