Thursday, 11 April 2013

I is for Immunis

I is for Immunis

All my posts for this A-Z Challenge Blog Hop will be themed around the Celtic/Roman Britain AD 71-84 era (at least that's my intention as I pen this on day 9)

There’s always something new to learn when I do new researching and I often think – well, that’s interesting. And there are other times when it’s more like- WOW!  Why have I not known this before?

During my recent research into the Roman military machine many things made much more sense to me about how the Romans were so successful as invaders. I always knew they were very organised, and that the Roman infantryman was skilled at more than the use of his blade and shield.

What had not been properly apparent to me was the scale of those who were named immunis. That a whole supply army was designated within a legion had somehow escaped my proper attention. Those people scurrying around in the background I had somehow equated all of them as slaves –but they weren’t slaves at all.

The immune class who accompanied the legion were amazingly skilled. They could turn their blade and defend themselves if necessary against hostile armies in Britannia, but in general fighting was not their purpose, and they did not usually perform the more menial dangerous tasks of ditch building or rampart guard duties.

Before gaining immune status a legionary soldier had to serve first as a tironis (6 months as a basic recruit); followed by a number of years as a militis (regular soldier) undergoing general training, after which (or during the latter part) they would acquire specialist skills. Promotion, or selection decreeing some form of acknowledgedment of them having gained sufficient skills, took place. Immune status could then be conferred on them. Once the immune status was achieved the pay was slightly increased.

So what type of job did the 'immunis' tend to do

Engineering– building for the legion was guided by the architecti (engineer) and agrimensor (surveyor) who orchestrated the construction of fortresses, forts and marching camps-organising labour for these from the general infantrymen. They also built the road systems that allowed swift passage of personnel and goods between fortresses and forts. Bridges were built by them, and they directed mining operations. 

During the era of my novel in some southern parts of Britannia the immune Engineers may have been instigating the building of Roman villas, town walls and houses, sewage and water ways for baths and piped water systems.

Artillerymen specialised in the use of the ballista and siege machines.

Versions of the ballistae were constructed on the Roman Navy vessels.

Drill and weapons instructors were often of the immune class
Medical staff who followed the legions were of immune status.
Carpenters who constructed the wooden interior fort buildings were skilled immunes.
Hunters Venators supplied the legion with meat from the hunt.

These are only a few of the possible jobs done by them.

Was it better to be an immunis, or a regular milites (infantryman) in the Roman Army? I’ll leave you to decide on that one!

In my sequel (work in progress) to THE BELTANE CHOICE I have a number of very secondary Roman characters who are doing an immune status job in morthern Britannia for the Legio IX. or Legio XX.


  1. The research you have to do is prodigious. Several years of Latin would be useful as well.

    1. I totally agree. I wish I had learned Latin.

  2. Hoo boy, I acknowledge you for your interest in researching such a topic. This was an interesting post, and I learned something I did not know.



  3. Hi Susan, I'm glad you got something new out of it. My next post's subject is maybe a litttle easier.!


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