For twenty-three years Philip had welded his growing Macedonia for war. Toughness was obligatory, and reflected in numerous anecdotes: Philip stationing his horsemen behind the lines to cut down any deserters, Philip refusing to allow women into camp, Philip berating a Macedonian for washing in warm water because in Macedonia only a woman who had just given birth was allowed to bath in comfort. Discipline was backed by plunder, foreign tithes, new farmland and the old gold mines which were seized on Macedonia's eastern borders and transformed to yield a solid supply of gold coin; a standing army could thus be supported, a luxury which only Sparta among the Greeks had braced herself to afford, and at once Philip began to teach it how to march. Whereas the infantrymen of Greek citizen armies would take one servant each to war with them, Philip allowed only one attendant to every ten soldiers; he banned carriages for his officers and forced them to march for thirty miles at a time in high summer or to carry thirty days' supply of flour on their backs when going out to summer camp. They were to rely on as few ox-drawn carts and mules for transport as possible. Stone hand-mills were taken to grind the corn in camp, and a regulation diet of bread and olives was only supplemented by plundered livestock, although Macedonia was also rich in fish and fruit, especially figs, whose high sugar content was thought suitable for soldiers. The army learnt to live off the land whatever the season, even if they had to scratch a living from native store-pits in the grip of a Bulgarian winter. For the first time, distance had ceased to matter in Balkan warfare.

This trained army was balanced by Philip's tactics, but great tactics are born less of originality than of a shrewd use of contemporary fashion, and Philip's army did not, like the goddess Athena, spring fully armed from its parent's brain. Greek society had seldom analysed its skills in technical pamphlets, but. warfare had been better served than arts as basic as mining or forestry, and the writings of such men as the general Xenophon were an accessible source of ideas both for oriental hazards and for the equipment of the horses which he so enjoyed. Infantry tactics were best learnt from example and discussion, and increasingly they had passed in the last sixty years from Greece's landed aristocrats to a new breed of common professionals, sons of a cobbler or a tradesman, who hired out their services abroad and spent most of their life in an army camp. Macedonia lay close to their operations, and in assessing Philip's army, the influences of Greek theory and professionals are central; Philip had inherited a siege train from his predecessor, but he hired his own Greek engineer, Polyeidus of Thessaly, and sponsored his inventions. 'A good deal of circumstantial evidence suggests that the principle of torsion was invented under the auspices of Philip II', who first applied spring of sinew or horsehair to the recently discovered arrow-catapult, doubling its range and power. Polyeidus also designed a system of toothed city walls and a siege tower 120 feet high, and he taught the pupils who devised ever stronger machinery for Alexander's siege-craft section. No Macedonian could have done it for himself.

On the battlefield, cavalry and infantry were Philip's two staple units, and he balanced them into a coherent line. On the right wing, the cavalry delivered the hammer blow, and in the centre, the infantry followed up like a heavy press; this was his standard tactic and Alexander's too, and it was held together by links of differing armour. Already it gave them an advantage. Because Greek infantry drifted to their right, or shielded side, generals usually placed their strongest units on their respective lefts, with the result that they never met in combat. The Macedonian right and left were equally balanced to upset their enemy's formation and their infantry never drifted from the centre; Philip may have learnt his line from the Theban general Pammenes who had entertained him in his youth at Thebes. As the punch force, the cavalry had the distinction of deciding the pitched battle, usually at the gallop; this method is spectacular, but many have failed to control it, for cavalry units are an unruly group of young bloods and gentlemen who only respond to a dashing example. This dash Alexander provided even more than his father, and his leadership turned the Companions into the finest unit of cavalry in history, Genghis Khan's included. For this, they had needed a proper home.

In southern Greece sparse summer grazing and a lack of men rich enough to own horses had mostly stopped cavalry from developing decisive style or numbers. But the feudal nobility of Macedonia were men born to ride and their European climate of glen and plain had given them watered pasturage. The highlands too had always grazed good horses, and by conquering the lush grass beyond his eastern borders in the first ten years of his reign Philip had won a broad acreage on which to settle nobles and a new class of landowners on new horse-pastures, until eight hundred Companion cavalrymen could be said to enjoy estates as vast as the total lands of the ten thousand richest men in Greece. Fertile estates meant more horses and revenues for a wider group of riders, and the number of Companion cavalrymen had risen from some six hundred or more at Philip's accession to some four thousand by the end of his reign. As for the horses, they were increased and varied by plundered mares from the barbarian north, a crossing which may have helped their speed. The horses of antiquity are coarse and heavy to an eye accustomed to Arab blood, and pictures on coins and paintings imply that Macedonian breeds had become heavier in the hundred years before Alexander. No stud books were kept of their lines, so improvement could not be planned; gelding was practised on most Greek warhorses and the technique of binding two wooden blocks to the testicles was as modem and effective as would be expected in a world well supplied with eunuchs.

The Companion rider was modestly defended. In art, he is never shown carrying a shield, though his attendant groom might. He wore the usual breastplates of leather or metal in various designs, fitted with armpieces for close combat when he took to using his sword or curved hunting scimitar. He had no stirrups and he sat on a saddlecloth which was strapped round the horse's neck and sometimes padded to protect his knees. Over his belted tunic he sported a flowing Macedonian cloak and a fringed skirt of leather or metal to protect his private parts; his shoes were characteristically Macedonian and opened at the foot like sandals, with no defences. His helmet resembled a fluted sou'wester of metal and was sometimes worn with a metal neck guard; Xenophon had recommended these items in his books on cavalry, and the distinctive helmet, which he had singled out for wide vision, was invented in Greek Boeotia where Philip had spent early years as a hostage. But of Xenophon's suggested metal leg shields and horse armour, the Companions copied nothing.

Techniques of skirmishing and wheeling had been developed by aristocrats and tribesmen, in the open plains of Sicily and the barbarian north, and these fluid manoeuvres were causing a favour in Greek tactics for lighter armour, javelins and a more distanced use of cavalry. Philip made no concessions to this. On the few occasions when the corseleted horsemen of Macedonia had been seen by Greek armies in the past hundred years, they had always astonished them by the plain shock of their charges, Philip did not discard this dramatic form of attack. Stirrups had not been invented, so a rider's legs could not be braced against impact and his lance could neither be stout nor supported under his arm. Nonetheless, the Companions surged into their enemy and lanced them. Their lances were fitted with a metal blade and cut from the cornel wood whose toughness Xenophon praised; they were so slender that they vibrated at the gallop and often broke on contact. Their use was mostly as a menace to scatter the line, whereupon men hacked and jostled against an enemy whom their bravado had unsettled. All Alexander's wounds from cavalry came from daggers and swords, not lances. However, the enemy too had no stirrups and experiment shows that a passing blow will topple a man without them, especially if he is heavily armoured.