<Li> Conduct a "siege" (siege - a military operation in which troops surround a place and cut off all outside access to force surrender): The Romans would typically build a wall around the existing city to help control the enemy . This wall would be built out of reach of the archers and would prevent the enemy from escaping . Once the Romans completed the wall, they would use catapults, ballistas and onagers to hurl rocks, spears, and other objects from safe distances . The ongoing siege would eventually cause the city / fort to run out of resources, thus causing the opponents to die off or surrender . </Li> <P> The basic principle behind these tactics was to disrupt their enemies' resources while increasing Roman resources . Without a regular supply of food, water, and other commodities, armies would begin to starve or dehydrate, resulting to low morale or killing of fellow soldiers . </P> <P> Strengths of the Macedonian phalanx . Prior to the rise of Rome, the Macedonian phalanx was the premiere infantry force in the Western World . It had proven itself on the battlefields of Mediterranean Europe, from Sparta to Macedonia, and had met and overcome several strong non-European armies from Persia to Pakistan / Northwest India . Packed into a dense armored mass, and equipped with massive pikes 12 to 21 feet (6.4 m) in length, the phalanx was a formidable force . While defensive configurations were sometimes used, the phalanx was most effective when it was moving forward in attack, either in a frontal charge or in "oblique" or echeloned order against an opposing flank, as the victories of Alexander the Great and Theban innovator Epaminondas attest . When working with other formations--light infantry and cavalry--it was, at its height under Alexander, without peer . </P> <P> Weaknesses of the Macedonian phalanx . Nevertheless, the Macedonian phalanx had key weaknesses . It had some maneuverability, but once a clash was joined this decreased, particularly on rough ground . Its "dense pack" approach also made it rigid . Compressed in the heat of battle, its troops could only primarily fight facing forward . The diversity of troops gave the phalanx great flexibility, but this diversity was a double - edged sword, relying on a mix of units that was complicated to control and position . These included not only the usual heavy infantrymen, cavalry and light infantry, but also various elite units, medium armed groups, foreign contingents with their own styles and shock units of war - elephants . Such "mixed" forces presented additional command and control problems . If properly organized and fighting together a long time under capable leaders, they could be very proficient . The campaigns of Alexander and Pyrrhus (a Hellenic - style formation of mixed contingents) show this . Without such long - term cohesion and leadership, however, their performance was uneven . By the time the Romans were engaging against Hellenistic armies, the Greeks had ceased to use strong flank guards and cavalry contingents, and their system had degenerated into a mere clash of phalanxes . This was the formation overcome by the Romans at Cynoscephalae . </P>

When did the greek alexandrian pike phalanx first engage the roman maniple in combat