A centurion's symbol of office was the vine staff, with which they disciplined even Roman citizens, who were otherwise legally protected from corporal punishment by the Porcian Laws.[citation needed] Centurions also served in the Roman navy. After the 107 BC Marian reforms of Gaius Marius, centurions were professional officers. In Late Antiquity and the Middle Ages, the Byzantine army's centurions were also known by the name kentarch (Kentarches).[1]