Taken together, Paul Cooper's Fall of Civilizations podcast episode on the Achaemenid Empire and Dan Carlin's Hardcore History series on Alexander the Great (still ongoing) paint a gorgeous, multi-faceted historical picture on a very large spatial and temporal scale.
With Achaemenid Persia, you could see the empire steadily coalescing under the capable hand of Cyrus the Great, famously besting the prophecy-misreading king Croesus among others, and defeating and annexing Medea and Babylon, in addition to Croesus' Lydia. The famous Achaemenid multi-cultural polity and policy, and religious tolerance began as genuine aspects of Cyrus' rule, but which would later be used as weapons, which we'll get to.
Besides their flexible and tolerant approach to empire-building, the Achaemenids advanced a number of impressive feats in centralized bureaucracy and governance, development of a civil service and a professional army, development of cutting edge infrastructure such as roads in the form of the Royal Road - parts of which are still in use today - and an organized postal system which were adopted by later empires. Culturally the Achaemenids were emulated by other cultures in many ways, including in fashion, with the eventual widespread adoption of pants for example.
As Achaemenid Persia conquered its surroundings, it would annex those territories while attempting to keep their local cultures and religions intact, allowing them to largely carry on their own governance, installing satraps to rule them as satrapies (territories under Persian control), who were amenable to the local population but who could also be counted on for loyalty, maintaining resource flows, and helping to provision the Persian military, among other functions.
As the empire expanded out to its full extent you could make out a growing dispersal of its power and vitality over a longer period of time, which happened both in its core through indications of a degradation of leadership and occasional usurpations and brushfire civil war - with an occasional talented ruler emerging - and out in its periphery though a degradation in the satraps themselves, as they ruled over crumbling satrapies, responding to pressures and shocks of their own.
Because after all the peripheral territories had histories of their own and local forces and interests to harness and manage to conduct their own governance, with local individuals competing for power and resources, which had to somehow be harmonized with the distant Persian interests. Starting in 499 BC, one particularly large series of shocks, known as the Greco-Persian war as a whole, demonstrates this process well. And the roots of this conflict go back to the empire's early expansion.
From a certain vantage point, that legendary Delphi Oracle prophecy that said Croesus would destroy a great empire if he went to war with Cyrus takes on a Moebius strip quality through the passage of time. To foreshadow a bit, the prophecy would end implicating the Achaemenid empire after all.
After gleefully misinterpreting the prophecy and charging into war, Croesus' empire would fall to Cyrus' army, clearing the way for the Persians' annexation of Lydia. But Lydia contained on its coast the Ionian Greeks who settled there after the Bronze Age collapse of Mycenean Greece, and these Greeks would be incorporated into the Achaemenid empire.
Over time, the Persians found the Greeks to be a troublesome bunch. The Greeks didn't have easily identifiable and stable native ruling elites to co-opt and rule through, only aristocracies made up of feuding factions that were difficult to get a handle on. So they ruled through local tyrants that they sponsored, who had the difficult task of maintaining power locally while remaining loyal to the Persians who supported them.
It was in 499 BC when this troublesome arrangement hit a snag. To cut a long story short, one of the local Greek tyrants, a gentleman by the name of Aristagoras, would find his political position in danger after a failed venture to shore up his standing at home and curry favor with the Persians. His joint venture with the satrap Artaphernes to carry out a siege on the island of Naxos ended in failure after a tangled mess of leadership conflicts and a protracted siege exhausted the expedition's resources.
Rather than risk political ruin or worse, Aristagoras incited the Ionian Greeks to revolt against the Persians, and they did. The revolt widened - which indicated existing issues with the Greek and Persian relations - with Sparta refusing support, but with Athens and Eretria agreeing to support the rebellion.
Despite the lively revolt, which went on for 6 years or so, the Greek offensive was not at full force and relatively fragmented, and the Persian response was decisive and apparently fair. The revolt was put down, and the lead perpetrators were hunted down and executed, and the rebelling provinces were brought back under Persian control.
However, underlying motivations in the Persian leadership were shifting from governance to revenge. The Persian king Darius vowed to punish Athens and Eritrea for their support of the Ionian revolt. He was reported to be like a dog after a bone, asking a servant to remind him of the Athenians some three times a day. He was also convinced that the rest of the Greeks were a threat to the stability of the empire anyway, and that they would eventually need to be brought under control.
As part of the first major invasion of Greece, in 492 BC the Persians re-subjugated Thrace and Macedonia after those regions became more independent after the Ionian revolt. However at 490 the Persians were defeated by Greece at the Battle of Marathon, and then Darius died before the invasion could continue. Darius' successor Xerxes was eager to carry on the invasion, with the empire working itself into a frenzy, but at this point, the invasion was uniting the whole Greek world, which would put up a more coordinated, spirited defense.
Xerxes enjoyed several victories, including a pyrrhic one after being delayed at the famous Thermopylae, which was an inspiration to the Greek world, motivating them to fight back hard, and eventually beat back the Persians. The final defeat of the Persians at Mycale encouraged the Greek cities in Asia to revolt and the Macedonians to regain their independence.
After the invasion ended in disaster, Xerxes was assassinated, and the Persians halted military operations in Greece. However after their victory, the Greeks would enter into their own period of dispersion, with Persia opting to hang back and take advantage of the growing disunity, seeking to wedge apart the various Greek powers, playing them against each other by picking favorites and funding them against their rivals, with that tactic figuring prominently in various conflicts, such as the highly destructive Peloponnesian war.
Athens' power and fortunes would come and go, with Persia backing the Spartans and the mainland Greeks against them. And then Spartan triumphalism and imperialism after the war would alarm the Persians, leading them to back an alliance of Athens, Thebes, and Corinth against Sparta in the Corinthian War. Athens' fortunes began to shift again, with them reclaiming lost ground, in the war, and alarmed, the Persians would throw their weight back behind the Spartans. After enough of that, when the Greeks were sufficiently weakened, that war was concluded with The King's Peace, which left Persia back in control of Ionian Greece, and the remaining Greek states as atomized, autonomous entities which were not allowed to form alliances, opening the door to perpetual Persian meddling indefinitely. Sound familiar?
In the face of the Greek defiance, Persian tolerance would turn into contempt and then open hostility, and they would weaponize their abilities to appeal to disparate cultures by instrumentalizing the aims of distant cultures such as the Athenians and Spartans, encouraging their disagreements and amplifying the momentum of the challenger of the moment, while throwing its weight against the victors who had gotten more powerful, so as to further disperse their energies. This long history of invasion and then the subsequent background meddling would instill a deep resent and hatred of the Persians in the Greek populations, which would have future consequences.
All of that dispersing Greek energy would then coalesce again in the rising Macedonian empire, firming up under the capable hands of Philip II, revolutionizing the army in the process, with his gaze turned towards Persia. A fascinating story in itself, but the post grows long.
To cut another long story short, eventually that consolidated empire, replete with a deadly and well-oiled war machine, freshly revolutionized, would be handed off to Alexander III, or Alexander the Great as we know him, after his father Philip II was assassinated. Alexander consolidated his legitimacy, quelling various revolts such as in Thebes so as to bring the rest of the Greeks under his umbrella. And this young ruler had a bottomless well of ambition and an unquenchable appetite for endless war. It was with these material capabilities and personal attributes that Alexander assumed his departed father's stance towards Persia, a hated enemy which presided over vast lands, resources, and treasure.
With that, Alexander launched himself and his Macedonian army into Achaemenid Persia, sweeping through that aging and weakening empire like a wildfire through so much dried-out kindling, spreading Greek culture and ideas all the while, like mycelium taking root in the sooty aftermath of scorched earth.
Alexander's conquest of the vast holdings of Persia were similar to the future Arab conquests, in that he arrived with a thunderclap, taking a staggering amount of territory in such a short amount of time, with his conquest lasting just as briefly. After exhausting his expansionary limits and then having his life cut short, Alexander's empire would fracture under civil war after his death, leaving behind Macedonia proper, Ptolemaic Egypt, the Attalid kingdom in West Asia Minor (now Turkey), and the Seleucid Empire in a large part of what is now known as the Middle East.
Later on I might fill in more of the latter half of this story, especially as Dan Carlin finishes his series on Alexander the Great, but that's enough for now. There was a general takeaway that I was most interested in expressing here. You can see these complexes of organized human activity - these empires - expand over time, fighting to maintain their shape with initial goals of governance and broad-based prosperity, goals which break down after the ravages of time and successive shocks deteriorate these structures, with power concentrating at the top, leading to king-driven processes of conquest, revenge, and extraction.
And different structures with different histories evolve differently, as we saw with the parallel development of the Greeks and Persians, which then interact with each other and influence each others' trajectories. And further, these structures evolve temporally as they expand, and come into contact with each other, and decline and collapse, and then reconstitute into something else, or reconstitute somewhere else, changing over time, which is something we can get more into another time too.
Fast forward to today, and we have this striking inversion, where the West as spearheaded by its US hegemon - what with its affinity for the ancient Greeks as its spiritual predecessors - struggles with a dissipation of its own as it shambles after Iran, which has dug into the mountainous region where the Achaemenid empire once stood, with the West seeking its revenge after various historical insults, its goodwill exhausted after 80 years of various smaller scale wars of aggression and perpetual meddling, seemingly unaware of the yawning chasm of hollowed-out capability, with a dim inkling of some kind of plan. A rabid dog after a phantom bone.
