- To cure a toothache, a Roman would take a bite out of a tree which had been struck by lightning, with his hands tied behind his back.
- The Romans found that one of the most effective ways to deal with the Carthaginian army's battle elephants was to get a pig, point it in the direction of the enemy lines, pour oil on it and set it alight. Nothing scares an elephant like a squealing flaming pig, apparently.
- A Roman century had only 80 soldiers in it, not 100 as you would expect (centum= 100). Originally a century did comprise of 100 soldiers, but when Marius reformed the Roman army he made the soldiers carry all their own equipment. There was no room in the tents for the extra equipment, so instead of making bigger tents, they kicked two guys out of each one, meaning that there were eight (rather than ten) men in each tent. The number of tents per century remained constant, and so a century was reduced from 100 to 80 soldiers.
The last two facts come courtesy of the remarkable James Adams.