Praetorium

The Latin term praetorium — or prœtorium or pretorium — originally signified a general’s tent within a Roman castra, castellum, or encampment. It derived from the name of one of the chief Roman magistrates, the praetor. (Praetor (Latin, "leader") was originally the title of the highest-ranking civil servant in the Roman Republic, but later became a position directly below the rank of consul.)

The general’s war council would meet within this tent, thus acquiring an administrative and juridical meaning that was carried over into the Byzantine Empire, where the praitōrion was the residence of a city's governor. The term was also used for the emperor's headquarters and other large residential buildings or palaces. The name would also be used to identify the praetorian camp and praetorian troops stationed in Rome. A general's bodyguard was known as the cohors praetoriae, out of which developed the Praetorian Guard, the emperor's bodyguard.