The idea of potestas originally referred to the power, through coercion, of a Roman magistrate to promulgate edicts, give action to litigants, etc.
The most important magistrates (such as consuls and praetors) are said to have imperium, which is the ultimate form of potestas, and refers indeed to military power.
Potestas strongly contrasts with the power of the Senate and the prudentes, a common way to refer to Roman jurists.
In a letter, Duo Sunt, Pope Gelasius I argued that Christendom was ruled, in theory, by the priests and princes.
[citation needed] The concept of plena in re potesta was often used in 13th-century Europe, of ownership as being "in full power" to do what one likes with one's property.