Imperial Roman military titles?

[Nathan Ross]

A propraetor was not appointed by the emperor, but by the senate, like a proconsul.

Just to confuse the picture further, most governors of imperial provinces were propraetors, senators appointed directly by the emperor - their full title was legatus Augusti pro praetore. Provinces with more than one legion were governed by men with proconsular authority, again imperial appointments; smaller provinces were governed by procurators from the equestrian order. Egypt, of course, was forbidden to senators and so governed by a high-ranking equestrian praefectus.