Unknown soldiers

The report on the Inversesk inscriptions prompts another thought...


It seems to have become de rigeur in the reporting of a new legionary centurion to attempt to identify him with some previously attested individual (or in this case to bring in individuals whom he cannot be identified with, which demonstrates access to a good database, but seems to add little otherwise [I am, of course, guilty of this myself] ). Little attention appears to be payed to the likelihood of this...

For that we need a few numbers - number of centurions, length of service etc - but data is sketchy, so we will only have broad estimates to play with, but enough to give an order of magnitude.

60 centurions per legion (round numbers); 20 years service; first 2 centuries AD; = 600 per legion
Average (low average) 25 legions = 15,000 centurions serving over this period.

How many do we know of already? Richier 2006 Centuriones ad Rhenum brings together 400-odd for the legions on the Rhine; c. 300 if we stick to the first two centuries AD and an average of 6 legions (8 in the first century; 4 in the second). Summerly 1991 Studies in the legionary centurionate was using Eric Birley's lists and as I recall his numbering got close to 1000 which fits quite well.

So we know the names of about 1/12th-1/15th of the centurions serving over this period. Sound quite good put like that, but 1/12th = 8.33%, ie we don't know the identity of 91.66% of centurions. The odds of a randomly recovered name matching one of those 8.3366% rather than being one of the previously unknown 91.66% are really not very high. Out of every 100 newly discovered centurions (and the rate of discovery is not especially high) we'd only expect 8 to be individuals already known...

...all things being equal. Which, of course they're not. Lots of factors pulling various ways. How many inscribed monuments would a centurion put up? Expensive things to commission. If a centurion was only likely to put up one or two, then once we've found one (or two), we're very unlikely to find another. Or perhaps certain centurions were more wedded to the 'epigraphic habit' and more inclined to leave their name in stone everywhere they went, in which case they would be easier to find. Not easy to know either way, but the main point stands. It's not actually very likely that we will already know of a newly discovered centurion. Certainly worth a comment if we do! Hardly worth noting if we don't.