Two centuries made up a manipulandum of 120 men. Each line of battle contained 10 maniples, 1200 men, except that the triarii numbered only 600. The legion of 4200 infantry created in this way was supported by 300 equities, or cavalry, organized in 10 Turmae (squadrons) of 30 horse each, under a master of horse (magister equisetum), who took orders from the legion commander. Cavalry was used for scouting, skirmishing and various sorts of clean-up — they also constituted another reserve that could be thrown into the battle. The Republic was ignorant of armies on horseback, which, coming off the steppes of Central Asia in blitzkrieg operations, were to trouble the later empire.