The tres militiae was a career progression of the Roman Imperial army for men of the equestrian order. It developed as an alternative to the cursus honorum of the senatorial order for enabling the social mobility of equestrians and identifying those with the aptitude for administration. The three posts, typically held over a period of two to four years, were Praefectus cohortis, Tribunus angusticlavius, and Praefectus alae.