In the Roman military, the orientation of the crista primarily served to distinguish rank and improve visibility: While ordinary legionaries usually wore their crests lengthwise (from front to back), centurions wore them crosswise so they were easily recognizable to their soldiers in the heat of battle. To secure the crista, it was either inserted into a central holder (loop or socket) on the helmet with a metal base and tied to eyelets, or, in the case of models with wooden or metal frames, attached using special crest holders for centurions or optios.