BC after the introduction of the aspis by the city of Argos, which would have made the formation possible. This is further evidenced by the Chigi vase, dated to 650 BC, identifying hoplites armed with aspis, spear and panoply. Another possible theory as to the birth of Greek phalanx warfare stems from the idea that some of the basic aspects of the phalanx were present in earlier times yet were not fully developed due to the lack of appropriate technology. Two of the basic tactics seen in earlier warfare include the principle of cohesion and the use of large groups of soldiers. This would suggest that the Greek phalanx was rather the culmination and perfection of a slowly developed idea that originated many years earlier. As weaponry and armour advanced through the years in different city-states, the phalanx became complex and effective. Overview The hoplite phalanx of the Archaic and Classical periods in Greece was the formation in which the hoplites would line up in ranks in close order. The hoplites would lock their shields together, and the first few ranks of soldiers would project their spears out over the first rank of shields. The phalanx therefore presented a shield wall and a mass of spear points to the enemy, making frontal assaults against it very difficult. It also allowed a higher proportion of the soldiers to be actively engaged in combat at a given time (rather than just those in the front rank). Battles between two phalanxes usually took place in open, flat plains where it was easier to advance and stay in formation. Rough terrain or hilly regions would have made it difficult to maintain a steady line and would have defeated the purpose of a phalanx. As a result, battles between Greek city-states would not take place in just any location, nor would they be limited to sometimes obvious strategic points. Rather, many times, the two opposing sides would find the most suitable piece of land where the conflict could be settled. Typically, the battle ended with one of the two fighting forces fleeing to safety. The phalanx usually advanced at a walking pace, although it is possible that they picked up speed during the last several yards. One of the main reasons for this slow approach was to maintain formation. The formation would be rendered useless if the phalanx was lost as the unit approached the