Arcani
Arcani, also called areani, were agents in Roman military units based in Roman Britain during the later part of the island’s occupation. They were used as both scouts of legions and secret spies. Many of them were mercenaries. This unit was disbanded by the father of the later emperor Theodosius I – Flavius Theodosius, for their participation in conspiracies.
The term arcani is hapaks legomenon, because we only know about the unit because of the Ammianus Marcellinus. Probably the members of the unit were residents living in the military zone between the Hadrian’s wall and the vallum in the south.
