Jobs within the auxiliary unit

These teacher notes provide information on the different jobs which existed within the auxiliary unit. You can download a copy of these teacher notes below.

Download: Jobs within the auxiliary unit PDF resource here (267 KB)

Illustration of infantry auxiliary soldier’s soft kit.
Illustration of infantry auxiliary soldier’s soft kit.

What jobs could soldiers do within the Auxiliary Unit?

These jobs are known to have existed in auxiliary units as they are recorded in inscriptions or in surviving documents. Exactly what each job entailed is not always clear.

Tiro = new recruit

Miles = rank and file soldier

Immunis = a rank and file soldier excused fatigues because of special duties

Principalis = category of those officers below the rank of centurion or decurion, who were paid either one and a half or two times the rate of a rank and file soldier

Staff in the office of the commanding officer

Latin title Job Comments
Cornicularius Chief clerk of unit Double pay
Actarius Clerk Below the cornicularius in rank
Librarius Clerk/copyist  
Beneficiarius Officer seconded by a superior officer for special duties Often lives outside the fort

Unit standard bearers

Decurio  Decurion, in charge of cavalry turma  Paid at least five times as much as a rank and file soldier; paid more than an infantry centurion 
Centurio  Centurion, in charge of infantry century  Paid at least five times as much as a rank and file soldier 
Signifer  Standard bearer and book-keeper  Double pay; one for each century and turma; usually had at least 15 years’ service 
Optio  Second-in-command to centurion  Double pay; sometimes called ‘duplicarius’ [= double] 
Duplicarius Second-in-command to decurion The term is also used generally of any soldier paid twice the normal rate 
Tesserarius  Officer officer below the rank of signifier and optio  Pay and a half; only in infantry. In charge of the daily password 
Curator  Soldier responsible for provision- ing (food and drink, fodder etc)  Pay and a half; only in turma (and possibly only in alae); perhaps same as a tesserarius 
Armorum custos  Soldier in charge of arms and armour  One in each century and turma 
Sesquiplicarius  Third-in-command in a turma  The term is also used generally of any soldier paid one and half normal rate 

Religious staff 

Aedituus or sacerdos Priest or keeper of shrine 

Hospital and medical staff 

Medicus Doctor, medical officer A medicus ordinarius was probably the same rank as a centurion; may have been appointed from outside the army 
Capsarius Medic 
Veterinarius Vet For cavalry horses 

Musical staff 

Bucinator Plays curved trumpet One or two in a unit 
Tubicen Plays straight trumpet 


Mensor Surveyor