Classiarii (singular: Classiarius; from Latin classis "fleet") referred to all military personnel (from the highest rank of praefectus classis to the simplest rank of miles classiarius) and personnel assigned to the maneuvering of ships (e.g., velarii or remiges) or their construction/maintenance (e.g., fabri navales), as part of the Roman navy, an integral part of the Roman army.