is not mentioned frequently in ancient Greek literature. There was a leader in each row of a phalanx, and a rear rank officer, the (meaning tail-leader), who kept order in the rear. The hoplites had to trust their neighbors to protect them and in turn be willing to protect their neighbors; a phalanx was thus only as strong as its weakest elements. The effectiveness of the phalanx therefore depended on how well the hoplites could maintain this formation in combat and how well they could stand their ground, especially when engaged against another phalanx. For this reason, the formation was deliberately organized to group friends and family close together, thus providing a psychological incentive to support one's fellows, and a disincentive, through shame, to panic or attempt to flee. The more disciplined and courageous the army, the more likely it was to winoften engagements between the various city-states of Greece would be resolved by one side fleeing before the battle. The Greek word (the "will to fight") expresses the drive that kept hoplites in formation. Hoplite armament Each hoplite provided his own equipment. The primary hoplite weapon was a spear around in length called a dory. Although accounts of its length vary, it is usually now believed to have been seven to nine feet long (~2.1–2.7 m). It was held one-handed, with the other hand holding the hoplite's shield (aspis). The spearhead was usually a curved leaf shape, while the rear of the spear had a spike called a ('lizard-killer') which was used to stand the spear in the ground (hence the name). It was also used as a secondary weapon if the main shaft snapped or to kill enemies lying on the ground. This was a common problem, especially for soldiers who were involved in the initial clash with the enemy. Despite the snapping of the spear, hoplites could easily switch to the without great consequence. The rear ranks used the secondary end to finish off fallen opponents as the phalanx advanced over them. Throughout the hoplite era, the standard hoplite armour went through many cyclical changes. An Archaic hoplite typically wore a bronze breastplate, a bronze helmet with cheekplates, as well as greaves and other armour. Later, in the classical period, the breastplate became less common, replaced instead with a corselet that some claim was made of linothorax (layers of linen glued together), or perhaps of leather, sometimes