Pezhetairos The pezhetairoi ( Greek : , singular : " pezhetairos " ) were the backbone of the Macedonian army and Diadochi kingdoms . They were literally " foot companions " ( in Greek , " pezos " means " foot warrior " or " infantryman " , and " hetairos " means " companion " or " friend " ) . The Macedonian phalanx es were made up almost entirely of pezhetairoi . Pezhetairoi were very effective against both enemy cavalry and infantry , as their long pikes could be used to impale enemies charging on horse - back or to keep enemy infantry with shorter weapons at bay . Description . The pezhetairoi were the battalions of the Macedonian phalanx . They first came to prominence during the reign of Philip II , particularly when they played such an important role in Philip ' s subjugation of Greece at the Battle of Chaeronea in 338 BCE . The name " foot companions " was used by famed commander Alexander the Great , the successor of Phillip II , as an ancient recruiting method . By labeling his infantry as his personal " companions " and " friends , " Alexander was able to engage a wider manpower base for his subsequent military campaigns , as positions in his personal infantry would denote pride and honor . Therefore , as Alexander would campaign across Asia , he was able to use his reputation as a brilliant military strategist , along with the personal connotation given to his infantry , to recruit more native peoples to his cause than conventional recruitment methods of the day . This created a near endless base of manpower for the burgeoning military leader , and allowed him to engage in longer , costlier campaigns in areas like Asia Minor , Egypt , Persia , and India . They were armed with the sarissa , a long spear with a shaft made from flexible cornel wood , which had a much longer reach than the traditional hoplite spear . Because of its length the phalanx could present the spearpoints of around five files of men ; which made the phalanx almost impenetrable , and fearsome to oppose . Tactically , the pezhetairoi were best used as a strong defensive line , rather than as shock troops . The length of the sarissa , while making them terrifying for an enemy to oppose , severely limited their maneuverability ; and if they were taken in flank or rear they had little chance of responding . This was particularly clear at the Battle of Gaugamela in 331 BCE , when the rapid advance of the right wing caused a breach to open between two of the battalions of pezhetairoi — a force of enemy cavalry broke through and , had it not been for a lack of discipline in their own command , and for Alexander ' s placing of a second line of traditional hoplites in reserve , the phalanx might have been destroyed from the rear . Apart from in pitched battles , the pezhetairoi and their sarissas were not very practical ; it is supposed that they were re - armed , and their tactics adapted , to suit the guerrilla warfare that was prevalent , and necessary , in Bactria and Sogdia . Asthetairoi . The Asthetairoi ( singular Asthetairos ) were the elite of the Macedonian Infantry . They were chosen Foot Companions , equipped with sarissa ( 21 feet long pike ) , argive shield , and short sword . They had mail - plate and bronze helmet . The Asthetairoi were the elite bodyguards of the Macedonian kings . Battalions . The battalions of pezhetairoi appear to have been organised on a regional basis , at least to begin with . We know of battalions named for the regions of Orestis / Lyncestis ( two battalions probably combining men from both regions ) , Elimaea and Tymphaea — if all pezhetairoi were from Upper Macedonia then we would expect the other battalions to have represented Eordaea and Pelagonia . In 334 BCE Alexander the Great took six battalions of pezhetairoi with him to Asia . By the time the army moved into India in 327 BC , a seventh battalion had been added .