the treasury was administered by three prefects "(praefecti aerarii militaris)", who were former praetors at first chosen by lot for a term of three years. later they were appointed by the emperor. their precise duties are unclear, though they were not charged with collecting the taxes. they may have served mainly to provide financial management and security. each senatorial prefect was assigned two lictors and other staff, but the later imperially-appointed prefects had no lictors. (the lictor was an honorary bodyguard who was part of the civil service of rome.) the change to appointment by the emperor may have been made as early as the reign of claudius. the younger pliny was a prefect of the military treasury appointed by domitian.