Definition: Imperium can be contrasted with potestas as a type of power Roman magistrates might have. Magistrates with imperium are the dictator, the consuls, praetors, proconsuls, and propraetors; magistrates with potestas are the censors, aediles, and plebeian tribunes. The difference between the two groups is that those with imperium had the power to command an army.
The power of Rome over a foreign nation is also described as imperium.
Magistrates with imperium were immune from prosecution during their time in office.
Sources:
- William Smith, D.C.L., LL.D.: A Dictionary of Greek and Roman Antiquities, John Murray, London, 1875.
- "Judicial Accountability and Immunity in Roman Law"
Joseph Plescia
The American Journal of Legal History (2001)
