to maintain. Terrain was uneven, injuries or deaths could cause gaps, simply someone tripping and falling could create problems. In the particular case of the Greek allies, the different contingents had not previously fought together and were assembled according to nationality. Forces so arranged would tend under pressure to gravitate toward their compatriots, which could cause gaps in the line. Given that the flanks were well guarded, Philip’s goal was to enable his son Alexander, who commanded on the left with the Companion Cavalry, to penetrate the Greek line.14 Whatever opposition cavalry appeared would be easily overcome by the superior forces under Alexander’s command. To accomplish the goal of penetrating the Greek line, Philip planned, after initial contact with the Athenians, for the Macedonian right, at Philip’s command, to begin a slow withdrawal up some rising ground near the foothills of the nearby mountain. This would stretch the Greek line, as the Athenians attempted to overwhelm their opponents (Polyaen. 4.2.2, 7).
The Athenians finding the enemies before them giving ground began what was apparently an over-enthusiastic and disordered advance. With the Athenians attacking wildly to their left and the Boeotian right maintaining its position along the riverbed, as Philip had planned, the allied center began to separate as these troops found themselves pulled between the Athenians moving to the left and the Boeotians standing firm on the right. For a time the battle was a struggle of competing infantries all along the line, but under the continuous probing of the Macedonian pikes, a gap or thinning in the line appeared through which Alexander and the cavalry charged, turning to attack the exposed Theban flank.15 Without stirrups, heavy cavalry could only attack infantry under special circumstances—when they fled, when gaps or thinning occurred in their line, or in assaults on the vulnerable flanks or rear. Here, direct assault would be possible, especially when charging in a wedge formation. Under these circumstances the momentum of the group served both to keep the pack in formation and to hit the line with tremendous force. The dangers in such an operation were great. If one horse in the front went down, it could lead to a cascading event. Also, if the infantry line was not broken by the initial charge, the cavalry was likely to be surrounded and overwhelmed by the opposing infantry.
After Alexander’s breakthrough, the Theban right wing, including the famous Sacred Band, found themselves fully engaged frontally by their Macedonian heavy infantry counterparts, and attacked simultaneously on their left and rear by the Macedonian Companion Cavalry. On the Macedonian right, Philip, having withdrawn to higher ground, stopped his feigned retreat and charged, breaking the spirit and coordination of the Athenian phalanx. With the Athenians in full flight, Philip’s right pivoted and attacked the allied line, which now broke and fled. The result was a crushing defeat for Philip’s enemies. A thousand Athenians lay dead, with 2,000 captured (Diod. Sic. 16.86.5–6). While numbers are not given for the Theban, Boeotian, and other allied dead, the totals were probably equally high, and the famous Sacred Band had been destroyed (Plut. Pel. 18.5).
While the core of the Macedonian infantry was composed of those bearing pikes (sarissai), as noted, modified hoplite armament was an important component of both Philip’s and Alexander’s Macedonian infantry. The troops were more flexible than the traditional sarissa bearers, even though, under the tutelage of Philip and Alexander, sarissa-bearing units were capable of moving quickly into varying formations, square, wedge, column, etc. but they required level and clear ground with no obstacles (Polyb. 18.31.5–6) and were ineffective in small units or as single soldiers (Polyb.18.32.9; cf. 11.15.7–16.3).16 Sarissai were weapons designed exclusively for the battlefield and in close array. As with broken ground, anything that could create gaps in the formation could spell disaster. Crossing broken terrain could also destroy a phalanx’s cohesion. At the Battle of Mantinea, a small ditch was sufficient to result in the defeat of the Spartan pikemen (Polyb. 11.15.7–16.2), and at Pydna in 168, while the Roman commander described how the Macedonian phalanx filled him with fear and amazement, that general drew it onto broken ground where it was annihilated (Plut. Aem. 19.1–3). In instances where roads were difficult or where speed was essential, “lighter-armed” heavy infantry would be used. Most importantly the sarissa phalanx was not very flexible. As Nicholas Hammond states, “[the sarissa] was unsuitable for skirmishing, besieging, street-fighting, ambushing, [and] mountaineering.”17 Despite Aristotle’s belief that “hoplites are useless without orderly formation” (Arist. Pol. 4.1297B), and even though they were most effective in, and designed for, warfare in the compact phalanx, hoplites were capable of individual combat especially against opposing troops in disarray when the cohesion of the enemy infantry collapsed, or in general against Asiatic heavy infantry forces that tended to wear less defensive armor. In all likelihood, Philip adopted the sarissa because this form of warfare was inexpensive. As noted, Macedon had no tradition of heavy infantry and the state, especially at the time of Philip’s accession, was not in a position to afford the equipment or pay for the training of a large force. Moreover, their training would have required more time than was typically available to the non-professional soldier. The use of hoplites was a different proposition entirely.
This use of combined forces is clearly seen in the Battle of Issus in 333 between Alexander the Great’s forces and those of Darius III (Arr. Anab. 2.8.5–11.7; Diod. Sic. 17.33–34). This clash took place in what is today southeastern Turkey very near the Gulf of Iskederun. Here the Macedonian king faced an army of far greater numbers; even though a total of 500,000–600,000 is mentioned in our sources for the total size of the Persian force (Diod. Sic. 17.33.4; Arr. Anab. 2.8.8), 100,000 infantry and 20,000 cavalry is a commonly suggested estimate.18 The Macedonian infantry was anchored on the right by the Hypaspists; the center was composed of the sarissa bearers, and the left wing covered by Greek allied hoplites. Alexander ordered his left wing to remain in contact with the sea in order to protect that flank from being turned by the larger Persian army. Alexander’s Companion Cavalry held the right, with the Thessalian cavalry and other Greek cavalry on the left. Those troops along the sea were to prevent the larger enemy forces from endangering his phalanx (Arr. Anab. 2.9.1).
In front of the cavalry on the right, Alexander posted the prodromoi (these were cavalry who carried longer pikes than the xysta used by the Companions), the Paeonian light cavalry armed with javelins and swords, archers, and the Agrianians. Other cavalry and archers screened the center. On Alexander’s left the light infantry comprised the Cretan archers and the light-armed Thracians. Other light-armed troops occupied the center in front of the phalanx. Numbers of Greek hoplites were kept in reserve. As the battle progressed, Alexander’s left was almost overwhelmed by the superior numbers of the Persians, but the Persian line became over-extended and a thinning occurred near its right flank. Into this weakness in the line charged the Companion Cavalry, in a wedge formation, followed by the Hypaspists. This charge, similar to the one at Chaeronea also led by Alexander, brought victory.19 The Greek mercenaries in Persian employ had held their own against the Macedonian phalanx and Alexander’s left was almost overwhelmed (Arr. Anab. 2.10.4, 11.2).
After Alexander’s death, in the great contest between Eumenes of Cardia and Antigonus Monophthalmus, the best generals among Alexander’s Successors, cavalry was again the decisive force in all three of their battles. In 319, Eumenes lost the engagement at Orcynia through the treachery of the Cardian’s cavalry commander who deserted in the the course of the battle (Diod. Sic. 18.40.5–8; Plut. Eum. 9.3). At Paraetacene three years later, it was Antigonus’ cavalry that salvaged a draw from what could have been an overwhelming defeat by exploiting a gap in Eumenes’ infantry line (Diod. Sic. 19.30.9–10) and roughly two months later won a victory by capturing Eumenes’ camp, which led to the latter’s surrender by his own forces.20
Hellenistic Innovations
While Philip’s and Alexander’s innovations changed the nature of warfare by introducing new weapons, new formations, and a greater use of combined arms, these were all, as one might say, variations on established themes. What was truly new to Hellenic warfare was the introduction of the elephant.21 Sometimes mistakenly compared to the tanks of modern warfare these impressively sized animals,
