In 1961, Oxford archaeologists uncovered a pit at the site of General Gnaeus Julius Agricola’s headquarters at Inchtuthil in Scotland. Unsavoury Caledonians had made his troops’ position untenable. So the Romans decided to quit their empire’s northernmost outpost, though not before going to extraordinary efforts to ensure they left nothing behind that could aid their enemies.
They dismantled and burned their fort. Then they dug a large hole into which they dumped their most precious metal items: 763,840 2in nails, 85,128 medium nails and 25,088 large nails. “These had held the fort together and would have been as useful as leaving a cache of weapons, so the Roman troops buried them,” writes Mark Miodownik, professor of materials and society at University College London. All other steel items were taken south: weapons, armour – and the soldiers’ razors, which “allowed the Romans to retreat clean-shaven, groomed in order to distinguish them from the savage hordes that had driven them out”.