Stationarius (Greek στατιωνάριος, stationarios or στατιονάρικος, stationarikos) was a temporary assignment of guard duty or policing functions for lower-ranking soldiers in military police detachments of the Imperial Roman army.Christopher J. Fuhrmann, Policing the Roman Empire: Soldiers, Administration, and Public Order (Oxford University Press, 2012), pp. 202, 211. Small detachments of milites stationarii held posts throughout Italy and the provinces where the military presence might otherwise be minimal.Fuhrmann, Policing the Roman Empire, pp. 132, 211. They take their name from statio, a general term for "post" or "station".Fuhrmann, Policing the Roman Empire, p. 207. While individual soldiers were typically transitory, the stations themselves seem to have been permanent, and stationarii were often identified by what station they held (for example, "stationarius of the Claudianus road").Fuhrmann, Policing the Roman Empire, p. 210.
Although it has sometimes been assumed that local people would resent a police presence,W.H.C. Frend, "A Third-century Inscription Relating to Angareia in Phrygia," Journal of Roman Studies 46 (1956), p. 52, called them "notoriously an instrument of tyranny," as cited by Fuhrmann, Policing the Empire, p. 219. in fact the evidence suggests they turned to stationarii for protection or intervention in criminal cases,Fuhrmann, Policing the Roman Empire, p. 197, 214, 224; examples given by Peter Thonemann, The Maeander Valley: A Historical Geography from Antiquity to Byzantium (Cambridge University Press, 2011), pp. 156–157. and even at times set up inscriptions in their honor.Fuhrmann, Policing the Roman Empire, pp. 219, 251. Stationarii are recorded in a number of varying inscriptions,Fuhrmann, Policing the Roman Empire, pp. 132, 157, 211. and are first attested by a collection of ostraka dating 108–117, during the reign of Trajan.Fuhrmann, Policing the Roman Empire, p. 208.
An assignment as stationarius appears to have been "grunt work," and it never appears among an officer's cursus honorum. Either the post was assigned to men of little potential, or it was considered too lacking in distinction to include in a résumé.Fuhrmann, Policing the Roman Empire, p. 251.
Other types of military police were the frumentarii, regionarii, and beneficiarii.Fuhrmann, Policing the Roman Empire, pp. 202, 207 (note 20).
As an adjective, stationarius has other uses that might imply private guards.Fuhrmann, Policing the Roman Empire, pp. 207, 210.
References
Further reading Petraccia Lucernoni, Gli stationarii in età imperiale (2001), a study collecting all known references to stationarii