Alexander the Great lives: How long does his empire last?

A published take on it

Melissa Scott published "A Choice of Destinies" in 1986 that has an interesting take on the core question. She places the POD in Alexander's decision not to invade India. It concludes with a prince of the blood on a space station in the equivalent of 1591.
 
Rome at this point is a monarchical city state. If Alexander turns West t some point the Macedoians will clash with the Etruscans. Rome may ally with Alexander in which case it survives until the Alexandrian Empire breaks up. Then it may become a contender to develop into a local successor state. In North Africa a Hellenised Carhage successor stat may rise gain to challange a resurgent Rome. I do agree we will see a much greater Hellennic influence in the Western Medditternean as well as in the East. More cultural and trading links will likely be the result of this.

Another question is the military impact. Does the Roman Legion still evolve or does the Phalanx continue as the dominant military doctrine?

They were a Republic long before Alexander's time.
 
Regarding the legion v phalanx, I think the phalanx would be overtaken by something else, to enable campaigns/conquests/etc to continue in regions where the phalanx wasn't so practical. The legion happened to do this very very well, so it became dominant very quickly. What might happen is that the phalanx survives longer, but only as a part of a 'combined arms' sort of army. After all, that's essentially what Alexander had anyway - his phalanxes didn't make up a great proportion of his armies.

The thing is, the phalanx under the successors were not used as they were traditionally meant to be used. That is, they were supposed to be a holding force, that fixed the enemy in place while the swooped around and plunged into their flanks and rear. The success of the phalanx depended on a strong cavalry force, of which only the Seleucid Empire possessed (look at what Antiochus III was able to do with a phalanx army when supplemented with a strong contingent of crack cavalry). This was true in phalanx vs phalanx engagements as well, as was proven in the battles Antiochus III engaged in against the Ptolemies.

Furthermore, originally, the phalanxes were far more flexible. Alexander was frequently able to use those men who made up his phalanx in tough hill and mountain campaigns, where they adopted tactics more like the peltasts and light hoplites of post-Peloponnesian War Greece than the rigid phalanxes of the Hellenistic era. The successors lengthened significantly the sarissa's used by the phalangites, making them more unweildy and their formations more rigid and less flexible. So when they were outflanked, or the front rows breached, reforming to deal with the threat was almost impossible. Compare this to the phalanx at Gaugamela, which was able to effectively deal with significant interruptions in their line and breakthroughs and hold off Darius until Alexander could return with the cavalry.
 
Agreed. The lessons of manoeuvrability v defensive strength are ones which recur throughout history. It could be argued that the pikeman formations of the mediaeval period were essentially the same as the later phalanxes - tight groupings of men with long pointy things, very good in fixed or slow-moving positions against attacks from the front, but vulnerable to flank attacks. It's human nature to think along the lines of, "this worked in the last battle(s) so it will work again."
Alexander's genius was his ability to adjust his use of his various types of soldier (phalanxes, skirmishers, light cavalry, companions, etc) depending on what type of army he was facing - if he'd kept using the tactics used in Asia Minor when he reached India, he'd not have done half so well. The successors just weren't as good (generally), so tried to keep using the 'proven battle winners'. It took a series of defeats of these 'battle winners' to prove that some more flexibility was required.
I'm therefore tempted to think that the phalanx might have survived longer as a recognisable part of the armies of the time if Alexander had lived longer, as he'd have adjusted its use to the threats faced and those various different usages would then have been inherited by his successor(s), whoever he/they was/were.
 
I think who if Alexander had lived longer his Empire wuold have likely survived his death more or less intact. The point is who the weddings of Susa (who were the true foundament of Alexander's intended Empire) happened just a year before Alexander's death. A son and heir of Alexander (who will never be his OTL heir) will be supported not only by the prestige of his father but also from the power his maternal family had over the majority of the Empire for a long time (a son of Stateira is the most logical choice as Alexander's heir, if she had none a son of Parysatis will be always favoured over one of Roxane). Alexander had not married two princesses of Persia for put them behind the daughter of an obscure noble of the Eastern frontiers... Stateira and not Roxane was the intended Queen and Parysatis the second bride. Stateira was the granddaughter of one of Alexander's biggest supporters and her sister and cousin were married to Alexander's closest companions.
So a survival of the Alexandrian Empire with the satraps' structure of the Persian Empire is very likely, considering who in this ATL is really unlikely Rome can be able to become powerful enough to threaten the Empire and OTL were first the division and then the rise of Rome to destroy Alexander's heritage
 
I'm in the minority, I think that the empire could have lasted in a respectable form for at least a century after Alexander's death. It all depends on who succeeds him and how smoothly it goes. The institution of leadership had to be tested and in OTL it failed but if you give Alexander a long enough life post-India then he can do some much needed tweaking of the Empire, allow the bloodmixing initiatives to bear fruit and maybe quietly retire some generals and keep the armies closer to Ctesiphon Babylon so everyone doesn't get a chance to landgrab at every succession.

Consider me in the minority as well.

The hardest thing with this scenario is actually Alexander living into his 50-s.
The rest is not that difficult to guess.

But let's say that during his Arabian campaign Alexander in his usual reckless suicidal manner got involved in the hand-to-hand combat. He fell from his horse, broke his both legs, had his right arm cut off, had a spinal injury and a handful of minor wounds. But he did not die, continued living able to move only in a stretcher/palanquin.
And he didn't kill himself quickly by alcohol as he had something like a religious revelation or something like that, becoming a true philosopher out of a suicidal fighter.

My point here is that Alexander living longer equals Alexander keeping his empire in the borders we know in OTL.
Which is understandable as he personally cannot lead his armies and at the same time he is envious to his generals - he cannot let anyone become as famous as himself. He was paranoid in OTL, he would be double paranoid in this ATL.
His generals would be entrusted with armies only when it's absolutely necessary - in case of invasions and punitive expeditions.

- What will the Empire look like?
- I guess, something like the Seleucid Empire of OTL.

But, there will be some differences:

1) it will be bigger of course. The Achaemenid Empire + Macedon/Greece. Most of the time, I guess with sporadic breaking away of some rebellious satrapies like Bactria or Egypt or some others.

2) The Hellenization will be different from OTL. The scale will be bigger, as from the very beginning the process will start from both ends - Barbarization of the Hellens/Macedonians and Hellenization of the "Barbarians". And it will be deeper, a little bit closer to amalgamation, like Alexander the Great desired.

3) But there won't be a "true amalgamation" of the conquerors and the conquered. This did not happen in OTL, that won't happen in ATL.
Because in this ATL there will be a great pool of the Macedonians/Greeks for the Empire, much bigger than in OTL Seleucid Empire or Ptolemaic Egypt. So there's even less incentive to rely on the locals in this ATL.

4) Military speaking the Empire will be much stronger than OTL Seleucid/Ptolemaic Empires. In OTL the power base of the Hellenistic kingdoms was dramatically small - the 'ethnic' Macedonians/Hellenes and the Hellenized local elites - about 3-5% of the total population at best.
Here in this ATL these Hellenes/Macedonians/Hellenized might be up to 10-20% of the total population of the Empire, which is a huge difference from OTL.
 
The empire will stand as long as Alexander lives, but after him it's an open question. Even with a peaceful succession.

And it's far from certain that Alexander will be able to subjugate Carthage at its height.

I like the scenario of Greece breaking away from a Hellenistic empire centered on Babylon. This empire would ultimately be seen by historians as a Greek speaking Persian dynasty.
 
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