Centurion grades, command, and promotion

Centurion was a grade of officer containing several levels of status and responsibility. A cohort still needed a commander even though the surviving evidence identifies no equivalent to an auxiliary prefect, making a senior centurion the likely choice. The excerpt tests competing promotion models, including a rigid progression through cohorts and a looser system in which grades outside the first cohort were closer in status. Appointment could follow long service in the ranks, time in the Praetorian Guard, or direct commission through wealth and local office. Inscriptions survive disproportionately from Italy and often omit earlier posts, so Roman officer careers cannot be reduced to a tidy ladder. Rank brought privileges, along with the duty to make decisions and accept responsibility.