The legate of a Roman Republican army was essentially a supreme military tribune, drawn from among the senatorial class of Rome (usually a consul or proconsul),[1] who acted as a second-in-command to the magistrate in charge of the force.
[2][3] This role was usually played by either seasoned generals or ambitious young senators; the latter option eventually displaced the military tribune as a path to gain recognition.
[3] After the changes in the army of the late Republic around the 1st century BCE (often referred to as the "Marian reforms", although the accuracy of this designation is disputed), the figure of the legate as a major second-in-command was eliminated.
[1] Initially, only conflicts on foreign ground had demanded the presence of legati, but the beginning of the Social War in 90 BC saw them being increasingly deployed in Italia.
The legate could be distinguished in the field by his elaborate Attic helmet and Lorica musculata or plumata, as well as a scarlet paludamentum (cloak), cincticulus (a sash tied around the waist) and a parazonium (status sword).
[7] The senatorial legatus legionis was removed from the Roman army by Gallienus, who preferred to entrust the command of a legionary unit to a leader chosen from within the equestrian order who had a long military career.