Alexander the third of Macedon, better known as Alexander the Great, was the architect of one of the world’s largest empires, an empire he created by leading an undefeated army to victories across Persia, Syria and Egypt. By the age of 25, he had accumulated the titles of King of Macedonia, Leader of the Greeks, Pharaoh of Egypt, and “great king” of Persia. Alexander then led his army a further 11,000 miles, founding over 70 cities and creating an empire that stretched across three continents, covering an area that extended from Greece in the west, to the Danube in the north, Egypt in the south, and as far east as the Indian Punjab.

Of all his achievements, Alexander’s most notable contribution was probably the way in which he revolutionized the art of war. Consider the following from the wikipedia entry on Alexander the Great:

“He never lost a battle, despite typically being outnumbered. This was due to use of terrain, phalanx and cavalry tactics, bold strategy, and the fierce loyalty of his troops. The Macedonian phalanx, armed with the sarissa, a spear 6 metres (20 ft) long, had been developed and perfected by Philip II [Alexander’s father] through rigorous training, and Alexander used its speed and maneuverability to great effect against larger but more disparate Persian forces. Alexander also recognized the potential for disunity among his diverse army, which employed various languages and weapons. He overcame this by being personally involved in battle, in the manner of a Macedonian king.”

In his book The Origins of War, military historian Arther Ferrill comments about Alexander’s military achievements as follows:

“After Alexander warfare would never be the same. He had carried the art to a level of sophistication that would rarely be equalled and even more rarely excelled for more than 2,000 years from his own day to the age of Napoleon.”

Alexander’s main contributions, which to a  large degree built on the achievements of his father, Philip, included four main components. The first was the creation of the integrated army, which has been referred to as the integration of  ”the infantry of the West” with “the cavalry of the East”. The second development was the logistical support of such an army, which is challenging due to differences in the speed of travel and attack of infantry and cavalry units. The third major development was the  formation of an engineering corps, which enabled a much more effective form of siege than had previously been possible. The final major innovation consisted of experimentation with and improvements on an infantry formation known as the phalanx.

Ferrill has proposed an interesting thought experiment to illustrate the far-reaching influence of Alexander’s tactics over the following two millennia. He suggests that we compare the achievements of the Macedonians of Alexander with those of Napoleon’s Grand Army in the battle of Waterloo against the British army of the Duke of Wellington. According to Ferrill, the purpose of the experiment is as follows:

“The best way to appreciate the qualities of Alexander’s generalship (and of his army) is to compare him in some detail with another well known general. For this purpose I have selected Napoleon – not arbitrarily, but because the comparison has often been made, in passing, by military historians. The comparison between the two generals is not far-fetched. By the Age of Napoleon the practice of war had obviously changed in many ways since the time of Alexander, but closer examination will reveal that the changes were not as great as one might imagine, and it will also illustrate the enormous contribution of Alexander to the art of war.”

Another military historian, E.W. Marsden, notes that both commanders faced similar strategic challenges as one prepared to invade Persia and the other, Russia. In both cases, conquest of vast territories controlled by a rival empire was involved. Ultimately, Napoleon failed while Alexander succeeded.

But how valid is a comparison of two figures separated by 2,000 years of history? First, it is important to note that the thought experiment received the support of several other military historians. Furthermore, Ferrill asks his readers to make the following concession in order to make a meaningful comparison:

“I ask (…) to set aside the consideration of the psychological impact of exploding gunpowder on Alexander and his men. There is no way of knowing what that might have been, though I am prepared to concede that it would have been great.”

The concession Ferrill is asking for is an important one. In the experiment that follows, we will be pitching Alexander and his army, as they fought the Persians in 331 BC, against Wellington’s army of 1815 AD. Arguably the most significant military advancement between 331 BC and 1815 AD was the perfection of the use of gunpowder. Ferrill argues that Alexander’s skill more than compensates for his lack of gunpowder and all other military advancements so long as we ignore the psychological impact explosions would have had on Alexander’s men.

The Battle of Waterloo, which took place south of Brussels near the village of Waterloo, matched Napoleon and his 72,000 of troops against the British army of  68,000. The British army, which included Belgian, Dutch and German troops, was commanded by Arthur Wellesley, Duke of Wellington. Ferrill describes Napoleon’s strategic ambitions early on the day of the battle:

“Napoleon’s plan was to storm Wellington’s position in a series of frontal attacks, and Marshal Ney was given tactical command of the French army while Napoleon stayed in the rear with the Imperial Guard, which was to be thrown into the fighting at the decisive moment. As David Chandler says, The Emperor was seeking a quick victory of an unsophisticated type. Napoleon himself is supposed to have said that ‘in half an hour I shall cut them to pieces’.”

In terms of the scale of the battle, both in terms of troop strength and geography, nothing about Waterloo would have been unfamiliar to Alexander and the Macedonians. They had fought opponents more numerous than Wellington’s army along lines of about the same length (indeed, ancient battles were larger and more sophisticated than is generally appreciated). The following illustration shows Alexander’s line at the Battle of Issus against the Persians as an overlay to a map of the Battle of Waterloo:

Battle of Issus against the Persians as an overlay to a map of the Battle of Waterloo
Battle of Issus as an overlay to a map of the Battle of Waterloo

Napoleon was exceptionally confident victory was his, estimating the odds at nine to one. Plans were even made for his staff to have dinner in Brussels that evening. However, the day turned out badly for Napoleon, who had made two crucial mistakes. Ferrill explains the first mistake and why, in his view, Alexander would have been quite unlikely to mimic it:

“Napoleon’s first mistake was in delaying the initial attack against Wellington for so long, a mistake compounded by the fact that Prussians were coming to relieve the British. Everything we know about Alexander suggests that he would not have been so sluggish and indecisive. At the Granicus and at Issus [the two first major battles the Macedonians fought against the Persians] Alexander moved from line of column into line of battle and attacked his enemy without delay. In his other battles he always moved vigorously, once he was in tactical range, to close with the enemy. Furthermore Alexander would not have mounted an attack either with cavalry or with infantry unsupported by the other arm.”

Napoleon’s second mistake was to position himself at the rear of the troops alongside his Imperial Guard. As the battle ensued, Napoleon was unable to intervene and affect the outcome in time. As Ferril notes, however, Alexander always positioned himself at the front of the troops, often leading the charge:

“Alexander would not have stayed behind his line the way Napoleon did. Wellington and Ney exposed themselves to risks all day long. Ney went through five horses on the afternoon of the battle, but Napoleon was so far behind his line that he could not intervene in tactical operations. He is reported to have been angry when Ney organized the French cavalry for the initial charge, but the Emperor was too far away to prevent it. Although Napoleon’s presence on the field, according to Wellington, ‘was worth 40,000 men’ (a statement that could be made equally well of Alexander), at Waterloo he dissipated this effect by remaining too far to the rear. That is a mistake that Alexander could not conceivably have made.”

He concludes with regard to Napoleon’s mistakes:

“All military historians agree that Napoleon and Ney made several critical mistakes on the day of Waterloo, and we can safely assume, based on what we know of Alexander’s career, that he would not have made any of them. It is of course theoretically possible that he might have had a bad day too, just as Napoleon did, but, unlike Napoleon, Alexander never actually had such a day in his own experience.”

There remains one important factor which might theoretically distinguish Alexander’s hellenistic warfare from that of the Napoleonic era: the invention of gunpowder and the use of muskets and artillery. Ferrill examined the influence of gunpowder on the Battle of Waterloo, and concludes that it played little part in the British victory:

“Since the British troops were able to protect themselves behind the ridge selected by Wellington, French guns did little damage. On the whole artillery was not an important factor in the battle of Waterloo.

Gunpowder would have been new to him, but he had some experience in using catapults as field artillery, at somewhat less range and destructive power. In fact neither French nor British artillery proved decisive at Waterloo. The battle was determined when cavalry and infantry, singly or in combination, closed with the enemy. The big guns at Waterloo could not prevent that from happening.”

He adds on the effect British artillery would have had on Alexander and his army:

“…it is doubtful that Alexander’s army would otherwise have been decisively affected by British firepower. Although Napoleon’s forces attacked in even deeper formation than the Macedonian phalanx, and were therefore a more inviting object of attack for British artillerymen, artillery did not prevent the French from getting within twenty yards of the British line in the fateful final assault. Presumably Alexander’s troops might have done that also.”

And on the effect of musket fire:

“Likewise the infantry musket was not an especially formidable weapon. Useless at 100 yards, it had some effect at fifty, but the injunction to ‘wait until you see the whites of their eyes’ was widely applied in Napoleonic warfare, and the Guard had approached to within twenty yards before Wellington turned his own forces against it. At a distance of twenty yards the Macedonian phalanx with its thirteen-foot lances would have been a greater threat to Wellington than Napoleon’s Guards. It is of course possible that British firepower might have broken their ranks just as it did, in conjunction with a bayonet charge, against Napoleon’s Guard. But a bayonet charge against the Macedonians would have been futile. Since it took several seconds to reload a musket, and the British had only two lines of musketeers, Macedonians within a range of fifty yards or less, trained as they were to charge at the double when necessary, could have closed with devastating effect against the British infantry. Assuming that they could have withstood the initial barrage of fire in which, admittedly, they would have taken heavy losses.”

With the threat of artillery and musket fire out of the way and a leveled battlefield, the Macedonian Phalanx left to its own devices would likely to have wreaked havoc on the British troops:

“Macedonian phalangites would have been vastly superior to British infantrymen in hand-to-hand combat. Alexander’s skirmishers would have been more effective at Waterloo than they were in antiquity. Bows and slings had a longer effective range than muskets, and, since warriors of the early nineteenth century wore little armour, arrows and slingstones would have done relatively more damage. The likely performance of Macedonian cavalry against British stirrups is perhaps more debatable, but the quality of Macedonian horsemanship was high, and the Macedonian cavalry lance was a fearsome weapon, French lancers caused the British so much trouble on the field at Waterloo that in the following year the British organised their own lancer units.”

Ferrill concludes his thought experiment with the following statement:

“Whatever Alexander’s performance on the field of Waterloo might have been, he had brought warfare 2,000 years earlier to a high water mark. The Romans later made improvements in the organization of infantry, but no other ancient general made as many basic contributions to warfare as Alexander the Great.”

Whether you agree with Ferrill’s conclusion or not, the very fact that a sensible comparison of a battle fought by Alexander’s army to one fought by Napoleon’s is at all possible is a testimony to the former’s remarkable achievements. Fast forward only 100 years, and a similar comparison to battles fought during World War I seem too absurd to consider.