Note 122 — THE AUXILIA DURING THE FIRST TWO CENTURIES A.D.

The principales would be the vexillarius alae, the optio singularium, and a duplicarius and sesquiplicarius to each turma. Of the immunes each turma has its signifer, custos armorum, and curator. The total number of the beneficiarii, &c., we do not know, but the inscription of the Equites Singulares quoted above suggests an average of three to a turma. In a cohors quingenaria with only 6 commissioned officers and 19 principales (the imaginifer cohortis and the signifer, optio, and tesserarius of each century) the chances of promotion would be less. This is another reason for the popularity of the cavalry and the desire of cohorts to become equitata. Cf. Tac. Hist. iv. 19.