Marius re-organized the Roman legion from a system of maniples into cohorts, as follows. The total number of men in a full strength legion was about 4,800 soldiers. The internal organization of a legion consisted of 10 cohorts of 6 centuries each. The century consisted of 80 men and was led by a centurion. Each century was divided again into 10 contubernia led by a decanus. The "contubernium" contained 8 legionaries. The century fought as a unit, marched as a unit and camped as a unit. The century carried with it all the arms and accoutrements required to feed and maintain it as a fighting unit. Each man was responsible for carrying his own supplies, weapons and several days' worth of rations (nicknamed 'Marius mules'). This logistical change drastically reduced the size of the baggage train required as support and made the army much more mobile. Between 2 and 6 legions grouped together constituted an army. The legions were kept in peak physical condition and discipline by constant training, one of the best in the ancient world. In battle, the cohorts were fielded in a more compact line than the previous maniple line to help improve morale and discipline.