#ancient espionage
- Arcani — A term designating a special unit of spies, scouts, or secret agents within the Roman army, primarily active in the province of Britannia during the 3rd and 4th centuries. Their structural role involved infiltrating enemy territories beyond Hadrian's Wall, gathering tactical intelligence, and reporting barbarian tribal movements, before being disbanded due to their complicity in the 'Great Conspiracy' of 367 AD.