The phalanx was subdivided into brigades, regiments, and battalions, and regularly officered. In marching, it was separated into these its constituent parts, and sometimes in battle it acted in divisions. It was stationed in the center of the army on the field, and on the two sides of it were bodies of cavalry and foot soldiers, more lightly armed than the soldiers of the phalanx, who could accordingly move with more alertness and speed, and carry their action readily wherever it might be called for. Those troops on the sides were called the wings. Alexander himself was accustomed to command one wing and Parmenio the other, while the phalanx crept along slowly but terribly between.