Historians have titled Alexander III of Macedon "the Great". In a very short period of time he conquered one of the largest empires in ancient history and was undefeated in battle.

What I'd like to know is, what factor more than any other made it possible for Alexander to achieve this?

Military historians typically focus on his battle tactics and strategies. Certainly those were remarkable and proven effective, but was that it? The Macedonian army he inherited was quite skilled; would Alexander have achieved the same given any other army in the ancient world? Would he have been equally effective against another ancient army, or were the particular opponents he faced particularly vulnerable to defeat?

I know there's probably no single answer, and it may well be a combination of factors, but I'd like to hear different theories.

  • Livy is of the opinion that Alexander would not have been quite as successful against Rome.
    – lins314159
    Commented Jul 15, 2012 at 23:31
  • He wouldn't have. When Perseus of Macedon fought the Roman army, the Macedonians found it hard to keep the line strait and their ranks unbroken, so once there was a gap, the Romans would rush in and massacre the people left and right.
    – Russell
    Commented Jul 16, 2012 at 2:02
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    The Roman legions were designed specifically to defeat Greece phalanx. Commented Jul 16, 2012 at 6:32
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    What all answers here, although not incorrect, are forgetting to mention, is that the central power of Persia had been slowly weakening for 150 years. That's why Alexander to a large extent was able to take Persia bit by bit. Commented Jul 22, 2012 at 15:23
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    Hm, anyone who's able to pursue the Scythian army for 20km while suffering from diarrhoea deserves to be called Great, imho. ;P
    – yannis
    Commented Dec 12, 2012 at 18:30

4 Answers 4


Against the Romans, Alexander would have lost. Several hundred years later, when Perseus of Macedon fought the Roman army, the Macedonians found it hard to keep the line strait and their ranks unbroken, so once there was a gap, the Romans would rush in and massacre the people left and right. The Macedonians with a ridged command structure and armed with pikes could do nothing. The gaps widened and more Romans poured in. The Romans started off with 38,000 and left the field with 1000 less men. The Macedonians started off with 44,000. and left the field with 25,000 less men.

If Alexander was given another army and enough time to figure out the strengths and weaknesses, he probably could have taken over some states. However, because politics and geography where different, he would probably not be as great. Alexander and Macedon were a state in northern Greece, who for much of its early history, was peaceful. This left The southern Greek states unaware and unprepared for the attacks from Macedon. If Alexander was king of Athens, he might not have been as successful since all he would have had was an unprofessional army and the Peloponnese League ready to pounce on him.

It also helped Alexander that to the east, the only real enemies he faced were the Persians. By this I don't mean that the Persians where incompetent, but rather, the Macedonian army only had to adapt tactics to fight one army. They didn't have to face the Carthegenians, the Gauls, the Greeks, and the Germanic tribes at the same time (Rome). Alexander's armies used the pike successfully against the Persians. The Persians were unable to adapt to the new weapon, and so, Alexander was able to defeat them.

When Alexander faced the Indians, he had less success because he had to form new tactics to fight them. He was repeatedly crushed by the elephant until he found how cowardly the elephants were and had them run and trample the Indian lines. He also found that India's dampness really didn't suit the metal armor and arms of his Phalanx. They all rusted.

Moving on to politics: if Alexander had been made a Roman general, he would face less success. In Rome, the generals' powers were quite limited, and were always fighting for power with the senate. When a general became popular, grew his army too large, or went too far away from Rome to be governed by the senate, the senate tended to take actions to limit his power. (Think back to Caesar) With this constant power struggle, it is doubtful that Alexander would have been so great.

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    That's a very interesting comparison of Alexander to Rome. The Roman army certainly was a force to be reckoned with, although at times it was better than others. For instance, they were repeatedly defeated by Hannibal, which makes me wonder how Hannibal and Alexander would compare...
    – Bryce
    Commented Jul 16, 2012 at 5:36
  • This makes a good presentation of the theory that Alexander's success was due to having a superior weapon (the pike) against a opponent (the Persians) lacking that technical development. This would argue that the Persians were basically doomed at this point and that anyone could have knocked them over; Macedonia just happened to be the one state with the ability to do it. If there was another sufficiently militaristic nation on Persia's borders, they could have achieved the same.
    – Bryce
    Commented Jul 16, 2012 at 8:16
  • @Bryce - Hannibal won against stunningly bad Roman generals. He fared much less well against Scipio. This is a common phenomena among history buffs - Everyone gets all excited for Rommel or Napoleon, leaving Patton and Wellington as after-thoughts. (And this is magnified a hundred-fold for the American Civil War. Everyone knows Quantrill, no-one knows Grierson.) In war, it's now how you start, it's how you finish. Commented Jul 16, 2012 at 11:54
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    @Bryce, continued: Your question asked "what allowed him to achieve this greatness?" not "what if he had attacked Rome, or what if he was in x position" so any real answer should consider the actual life and actions of Alexander and the actual circumstances in which he operated, not asinine postulates of might-of-been's...
    – Ryan
    Commented Sep 4, 2015 at 22:38
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    A bit like saying "Napoleon would have been really bad against tanks and machine guns". Apples and oranges.
    – DevSolar
    Commented May 3, 2017 at 11:21

The Greeks had demonstrated military superiority over the Persians for many years. Both Cimon and Agesilaus had led successful expeditions into Persian territory. That Persia maintained its dominant position over Greece had not so much to do with their own military capabilities, but rather because of the incessant warfare amongst Greek cities. Their focus on destroying each other drained their resources and enabled Persia to make territorial gains in exchange for money supporting one side or another in the Greek wars. Plutarch lamented that when Agesilaus met with success in Asia Minor and was intending to march on to the Persian capitals, he was instead ordered back to Sparta by the ephors to fight against other Greeks.

The Macedonia that Alexander left behind was very different to the Greek city states. Alexander did not have the restraints imposed by ephors, voters and term limits, so had much freedom in his military planning. Macedonian conquests under Philip and during Alexander's early reign set the foundations for the conquest of Persia. The subjection of their neighbours, including a weakened Greece, enabled Alexander to march without fear of suffering Agesilaus' plight. The conquered wealth, including from the gold mines of Amphipolis, could pay for a military substantially larger than that under Agesilaus while still leaving enough troops to protect the homeland. The allure of Persian treasure was also a great incentive for those in the much poorer Greece to take to arms.

I do not share Livy's assessment that Alexander would have failed against Rome. The situation of Perseus is not a valid comparison. At that time, Rome was already the dominant power of the western world while Macedonia had lost much of its power and was commanded by less capable generals. A better choice would be the example of Pyrrhus, commanding a smaller territory and fighting some 50 years later when the Romans had grown in power, who was successful in battle against the Romans but ultimately lost the war due to insufficient reserves. Alexander was better resourced and would not have had this problem. More importantly, the Romans had not in Alexander's time adopted the tactical changes that would give them superiority over phalanxes in later years, so he would also not suffer as severe losses as Pyrrhus did.

Alexander would not have been able to defeat Carthage, as that would have either required naval superiority or a massive overland march.

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    I like it. This theory argues that the Greek armies were superior to Persia's armies, but it required the political alignment and unification of Philip's Macedonia to enable the conquest. So Alexander in this view was simply the right man in the right situation, if Philip had another son he could have done as well as Alexander.
    – Bryce
    Commented Jul 16, 2012 at 8:13
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    Well, Philip's other son Arrhidaeus could certainly not have done it. Plutarch thinks that Agesilaus could have beaten Alexander to the Persian throne had he not been called back. I don't agree given the far smaller numbers that Agesilaus had, but I do think that he would have succeeded had he been in Alexander's situation.
    – lins314159
    Commented Jul 16, 2012 at 10:02
  • I respectfully disagree with your point regarding Alexander The Great and Carthage. Although Carthage was a Major naval and commercial power throughout the Mediterranean region for several centuries, the Greeks had an equally impressive and centuries old navy and global commercial presence within the Mediterranean-(as well as Black) Sea regions. If Alexander had gone westward-(instead of eastward) and confronted the Carthaginians, in all likelihood, he would have had the unification of Greece-(or at least most of Greece) and nearby Greco-Anatolia(or at least most of Greco-Anatolia).
    – user26763
    Commented Oct 18, 2017 at 0:52
  • With this likely Hellenic unification, Alexander would have probably continued on to the Greek cities in Southern Italy & Sicily, as a way of establishing a wider/greater Greco-Mediterranean block, from Naples, to Ephesus which may have concerned the mighty Carthaginian Empire. Such a geographical block would have inexorably produced a major Hellenic naval presence-(especially emanating from Athens), which may have been a formidable match for the Carthaginians.
    – user26763
    Commented Oct 18, 2017 at 0:57
  • As for Rome, Alexander and his Greek military may have defeated the Romans at sea. However, if it was only land based battles, in all likelihood, Alexander and the Greek military would have probably lost to the stronger and more sophisticated Roman Army.
    – user26763
    Commented Oct 18, 2017 at 0:59

I voted up lins314159's answer. I would like to add a couple of things though.

The vast majority of Alexander's empire actually started his tenure as the Persian's empire. So a great deal of credit (and attention) should be paid to all the work they did to put that empire together.

However, Persia's loss of the Persian-Greek wars 100 years earlier had established that Greek arms were superior. After that, what kept the Greeks in check was mostly Greek infighting (which Persia happily subsidized). At this point, Persia's biggest nightmare would be the Greeks uniting and turning against them.

Enter Phillip of Macedon (Alexander's dad). Probably the one thing he had that nobody else in Greece had was rich silver mines in his territory. In fact, the first place he took was Amphipolis, which contained the silver mines (and some gold too). Wikipedia talks a lot about Phillips expert diplomacy and his military buildup, but both were financed with Macedonian silver. Using those resources, he slowly conquered or acquired the submission of all of Greece, save Sparta (and Crete, if it counts). enter image description here

Then he was promply assasinated, leaving his heir Alexander with a huge and expensive army to feed, and the hapless Persians right next door...

  • I'd also like to point out that the Persians were kind of the heroes of a lot of the Hebrew Bible. They get a bum rap from popular media and in a lot of history books (at least English language ones I've seen).
    – T.E.D.
    Commented Jul 16, 2012 at 17:32
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    +1 for mentioning what Alexander inherited from Persia. Logistics would have been a lot harder without the well planned road systems of a large empire.
    – lins314159
    Commented Jul 17, 2012 at 5:02
  1. The Charisma - Macedonian soldiers were ready to go with Alexander, because they loved their leader and didn't just go with him because of fear of him.

  2. The War techniques - Alexander was "great" at designing new techniques at war. For example, He let the war chariots go inside his line and made his warriors attack the chariots from behind. The chariots then weren't able to attack the soldiers behind them. Literally, this technique made the war chariots become useless for backward attack.

  3. The desire - As per my studies he had grown up with the dream of "EAST".:)

  4. He did everything as if he was predestined to. So that he has become "Great".

  • Could you clarify the third point? I don't understand what you mean by "like cameo"?
    – Bryce
    Commented Jul 16, 2012 at 5:33
  • hmm..i meant he just came(up to India),won and dead so fast like no other.:)
    – Veera Raj
    Commented Jul 16, 2012 at 5:52
  • This theory argues it was something intrinsic in Alexander that enabled the conquest to occur.
    – Bryce
    Commented Jul 16, 2012 at 8:21
  • I believe that Veeraraj means "cameo" like "talisman", what would be said in English as either "good luck" or "predestined". Is this right, Veeraraj?
    – dotancohen
    Commented Jul 25, 2012 at 6:12
  • @dotancohen>>predestined ..:))))..yes
    – Veera Raj
    Commented Jul 26, 2012 at 18:51

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