A while back I posted about how VIIII not IX was the ancient way of writing for The Ninth Legion. A recent comment by Duncan Campbell (thank you!) on that post reveals the limits of my knowledge. He writes that to say, as I did, that “The use of IX is a modernism, the Ancient use of the number would have been VIIII” is “not strictly true”.
Fifteen different versions of the Ninth Legion’s tile stamp are known — whenever Roman military units manufactured tiles, they tended to stamp them. Those found in the vicinity of York (Eburacum) were stamped LEG IX HISP, but those found in the vicinity of Carlisle (where there was a major tilery) were stamped LEG VIIII or LEG VIIII H.
The latter version also turns up in the vicinity of Nijmegen in the Netherlands, and is one of the main reasons for our current thinking that the legion was transferred from Britain to the Continent, either by Trajan or by Hadrian.