1. The system of government in ancient Rome under the emperors, especially from Augustus to Diocletian, in which the emperor held supreme power while maintaining the forms of the Republic.
Usage: historical; often capitalized when referring to the specific period
2. The office, rank, or period of rule of a prince or chief ruler.
Usage: formal; archaic

Examples

• The principate of Augustus marked the beginning of the Roman Empire.
• During the principate, emperors claimed to respect republican institutions while wielding absolute power.
• Historians distinguish the principate from the later dominate period of Roman rule.
• The principate lasted approximately three centuries before the empire's administrative structure changed.
• Augustus established the principate as a compromise between monarchy and republic.