Praetor peregrinus

Praetor (Classical Latin: [ˈprajtoːr]) was a title granted by the government of Ancient Rome to men acting in one of two official capacities: the commander of an army (in the field or, less often, before the army had been mustered); or, an elected magistratus (magistrate), assigned various duties (which varied at different periods in Rome's history). The functions of the magistracy, the praetura (praetorship), are described by the adjective: the praetoria potestas (praetorian power), the praetorium imperium (praetorian authority), and the praetorium ius (praetorian law), the legal precedents established by the praetores (praetors). Praetorium, as a substantive, denoted the location from which the praetor exercised his authority, either the headquarters of his castra, the courthouse (tribunal) of his judiciary, or the city hall of his provincial governorship.

The Classical-era authors do not describe the events leading to the Praetor title origination, but the writings of the late Republican statesman and attorney Cicero explored the philosophy and uses of the term praetor.

The prefix prae is a good indication that the title-holder was prior, in some way, in society. Livy mentions that the Latini were led and governed in warfare by two of them and the Samnites by one. A dictator was called the praetor maximus. The use of the adjectives (praetorius, praetoricius, praetorianus) in a large number of circumstances testify to a general sense. The leadership functions of any corporate body at Rome might be termed praetorial.

The praetoria potestas in Republican Rome was at first held by the consuls. These two officials, elected on a yearly basis, inherited the power of the king. Very likely, the king himself was the first praetor. The best explanation available is that of Cicero in De legibus, in which he proposes ideal laws based on Roman constitutional theory:

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