top of page
  • James Houser

415 BC - The Sicilian Expedition

Updated: Jun 17, 2021

NOVEMBER 22: 415 BC. The tenuous peace between Athens and Sparta is broken once again when Athenian general Alcibiades proposes a crazy plan to invade distant Sicily. This bold stroke will turn into disaster, one of the greatest acts of hubris known to man, and turns the Peloponnesian War firmly against Athens. Join me today on one of the most legendary acts of folly in human history: the Sicilian Expedition and the Siege of Syracuse.

Why do smart people make bad decisions? Why do assemblies of some of the most brilliant minds of their time often fall into the most obvious traps, the most illogical trains of groupthink, and the most outstanding acts of folly? This is not just a question of classical history. Incredibly smart groups of talented individuals fall into disastrous courses of action with astonishing frequency even in our own times, let alone in ages past. But rarely have any of these instances been as immediately disastrous and ultimately fatal to a whole society as Athens’ disaster in Sicily.

To compare the Sicilian Expedition, I can muster up three examples. In all these cases, the most enlightened and sophisticated institution of its age made unforced errors that resulted in permanent damage to their institutions. First: the Papal greed, neglect, and lavish spending that led directly to the Protestant Reformation. Rome was the intellectual and cultural capital of Europe in the early 1500s, so you’d think that all these great minds could have seen what was coming. Second: the intellectually complex and triumphant world of George III’s Britain made a series of dramatically stupid decisions that led to them losing the richest and most profitable part of their Empire, the Thirteen Colonies. Finally, the global imperial power, the arsenal of democracy, the Best and the Brightest at the head of the U.S. government in the 1960s made choices that sucked them into the quagmire of Vietnam and permanently damaged American trust and faith in their elected officials.

All of these vignettes - drawn from Barbara Tuchman's book The March of Folly - were examples of maybe the smartest collection of people in the world in their time, and all of them made disastrous decisions through groupthink, unexamined premises, irrational thinking, and especially a smug sense of superiority and hubris. But none of them made bad choices that so directly threatened their security, their fortunes, or their very existence as did the Athenians in making the decision to invade Sicily. This was the turning point of the Peloponnesian War, the major disaster that finally put Sparta in a position to destroy Athens – though that would not come to fruition until some nine years later. Either way, the Sicilian disaster would not just mark a turning point in Athenian fortunes but in the history of the world…which I will explain at the end.

So if you’re one of the probably NO people who have been keeping up with the Peloponnesian War saga, Athens and Sparta concluded a peace settlement in 421 BC after over a decade of fighting. (I will post the links in a comment below.) The war had been absolute hell on both cities, since Athens had suffered a terrible plague and despoilation of their lands – but Sparta had suffered humiliating military defeats and was able to force little more than a stalemate against the overwhelming naval and economic power of Athens. The Athenian general Nicias negotiated a peace in 421 BC that was SUPPOSED to put an end to the war – but didn’t.

While Athens and Sparta were ready for peace, many of their allies weren’t. The Peloponnesian War did not end with the truce in 421 BC, but continued as minor skirmishes and inter-city wars flared up across Greece, with Sparta and Athens supporting their own factions but always drawing back from direct military confrontation. In 418 BC, the Spartans faced a coalition of Greek cities led by Argos, their neighbor and old rival for control in that section of Greece. Though Argos was supported financially by Athens, and some Athenian soldiers even fought for Argos on the downlow, Sparta won the Battle of Mantinea in 418 BC. This was the largest land battle of the Peloponnesian War, and assured the survival of Sparta’s alliance during the Peace of Nicias.

The Athenian force at Mantinea had been led by a young, charismatic figure named Alcibiades. I will say a LOT more about Alcibiades in the next Peloponnesian War post since he is one of my favorite people in history. Young, brilliant, egotistical, handsome and scheming, Alcibiades had become the leading pro-war and anti-Sparta figure in Athens after the Peace of Nicias. Alcibiades was a student of Socrates and a persuasive speaker with an innovative mind and a strident tone. In contrast, Nicias himself continued to lead the faction in favor of maintaining the peace and reconciling with Sparta. Nicias was a conservative, taciturn older figure who was always more cautious in his approach to diplomacy and politics.

The truce between Athens and Sparta was obviously not built to last. The previous open conflict had resolved nothing, since the two cities still feared each other and their respective allies continued to clash. In addition to their allies on the Greek mainland and islands, both cities had interests in Greek settlements across the Mediterranean – especially on the island of Sicily. For the unsure, that’s the triangular island just off the toe of the Italian boot. Sicily was mostly Greek at the time, with multiple cities founded by settlers from cities on the Greek mainland. The most important city by far was Syracuse on the southern tip of Sicily, which had been seeking to dominate the other Sicilian cities. Syracuse was an ally of Sparta and Corinth, and had been sending food supplies to them during most of the Peloponnesian War.

Syracuse’s activities prompted the Athens-allied Sicilian city of Segesta to send a delegation to their more powerful friend, begging for support against the power of Syracuse. This put Athens in a difficult position. Though they wanted to help their ally, they were also concerned that intervention in Sicily would be a drain on their resources and antagonize Sparta, shattering the Peace of Nicias. The debate over whether or not to intervene in Sicily would be one of the most momentous in Athens’ history.

Alcibiades, of course, favored intervention. Before the Athenian Assembly (remember that Athens was a democracy), he spoke of the strategic benefits of controlling Sicily, including cutting off food and resources to Sparta in the event that the peace broke down. But then he went farther, talking about the long-term benefits of adding not only Sicily, but the rising powers of Carthage and Italy to their Empire. (This would have included the still-small power of Rome.) Alcibiades dangled glorious visions in front of the Athenian Assembly – dominance over the Western Mediterranean, the total outflanking of Sparta, complete victory for a small price.

In contrast, Nicias voiced caution. He raised a number of good points, including the cost and risk of the expedition, and asked whether this was really worth so much Athenian energy. Sicily was at best peripheral to the mainland Greek world, and would have little direct impact on Sparta and its allies. Not only would Athens commit too much of their force to a distant theater, leaving their enemies closer to home in an advantageous position, but they would spread themselves too thinly trying to conquer all of Sicily – including the great city of Syracuse, which was almost as large as Athens itself. Finally, Nicias attacked Alcibiades as inexperienced and glory-seeking.

The Assembly was clearly leaning towards Alcibiades’ promises, though. One of democracy’s great downsides is that the man who promises the most often wins, whether or not he can deliver. Nicias tried a different tactic: rather than the 60 ships Alcibiades proposed, Nicias claimed that to subdue Sicily would take a far larger force than he believed Athens was willing to risk. He said that over 100 ships and 5,000 hoplites would be necessary for such a risky expedition. This tactic was designed to make the Assembly stop and think about what they were doing, but it backfired. The Assembly enthusiastically endorsed Nicias’ proposal, leaving him lost for words. His ploy had utterly failed, and the number of ships and men that they now wanted to risk wouldn’t just mean defeat if worst came to worst – it would mean disaster. Nicias, by trying to prevent the Expedition from taking place, had only made its possible failure more terrible.

Athens as a city pitched into a frenzy of preparation for this expedition that promised so much. They pitched all the money and resources that they had built up over six years of peace into the expedition. Athens sent its best men, its best ships, and its best weapons. Their hopes for total victory outshone their prudence, their logic, or their reason. Was it wise to commit so many of their city’s resources on a distant expedition that may or may not return its investment? Was Sicily really the place to wager the fate of their city? No one asked these hard questions, and they prepared for the glorious venture that was sure to bring their city fortune.

The Assembly selected Alcibiades to lead the expedition, but they were still suspicious

of his character. He was famously volatile, young and brash, so they made the decision to send Nicias along as his second in command, hoping the older general could mediate Alcibiades’ reckless urges. In addition, they sent a third general named Lamachus to negotiate between the two; the result was a divided command that disagreed on the very purpose or goal of the expedition, and a situation that could not end well.

The Sicilian Expedition set out in 415 BC, but even its launch was marred by a bad omen. On the night before the expedition’s launch, an unknown vandal desecrated many of the statues of Hermes that dotted the city. These statues were supposed to bring good luck, so their desecration on the night before the Expedition’s launch was a grave sign of events to come. Some of Alcibiades’ political rivals used a supposed witness to accuse him and his friends of the deed, but when Alcibiades demanded a trial they backed down. No matter; after the Expedition set out, these same enemies entered the charges anyway. Without the young firebrand around to defend himself, they would surely succeed.

The Athenian expedition – almost 27,000 men including 7,000 ground troops, 134 ships, and its most prominent leaders – sailed along southern Greece and the boot of Italy before drawing up on Sicily itself. This was an enormous portion of the resources of Athens and its allies, and it was completely committed to Syracuse. The Syracusans themselves had ignored warnings of the Expedition until it was nearly in sight. However, disagreements among the Athenians screwed up the plan. Nicias had learned that the ally Segesta had not fulfilled its promises and the cause of the intervention was null and void; he wanted to abandon the mission. Lamachus wanted to launch a preemptive strike on Syracuse to take advantage of surprise. Alcibiades, though, wanted to travel by land across the island and surround the city. His oratory won out, and the Greeks adopted Alcibiades’ plan. This decision gave Syracuse time to fortify their city, recover from their initial surprise and – most importantly – seek out help from abroad.

Word soon reached the Athenian expedition, though, that Alcibiades had been tried and condemned of sacrilege in absentia, and that he was required to return for sentencing. This shocking news caused Alcibiades, reasonably fearing for his life, to make a break for it. He escaped his captors and fled to, of all places, Sparta. The defection of Athens’ lead general was one of those great unforced errors that Athens could clearly have avoided with some common sense. At Sparta, Alcibiades revealed the entire Athenian plan to his new hosts. Though Sparta still resisted breaking the Peace of Nicias, even with this Athenian defector’s advice, they soon received emissaries from Syracuse begging for help. The Spartans finally decided to allow the Corinthians to send a fleet to help Syracuse, and more importantly they sent a Spartan general named Gylippus to take command at the city.

So already the Athenian plan was derailed. Their top general had betrayed them to the Spartans, and this whole thing had been his idea. Nevertheless, Nicias and Lamachus led the Athenians in an assault on Syracuse in the later part of 415 BC. They won a limited victory, but thanks to Syracusan preparations could not win a decisive one; worse, Lamachus was killed, leaving the cautious Nicias in sole command of the Athenian force. This is when the Athenians could have used Alcibiades’ brilliant and risky leadership. Instead, Nicias settled in to surround and besiege Syracuse slowly, building a wall around the city by land and using the fleet to cut them off by sea.

The Athenian strategy did not work. The Syracusans raided the Athenian army constantly, keeping the wall from ever being completed. Despite these successes, the people of Syracuse were leaning towards surrender until the Spartan general Gylippus slipped the blockade. This, once again, demonstrated Sparta’s true military advantage, which was never the superior fighting ability of their soldiers. The very reputation of the Spartans inspired confidence and promoted cooperation, and Gylippus put some spine into the Syracusans. Under his leadership, they outfoxed and outmaneuvered Nicias, even building a counterwall to stop the Athenian building effort and secure a pipeline to the rest of the island. Gylippus’ intervention had saved Syracuse from imminent defeat.

After a year’s campaigning around Syracuse, in 414 BC the disheartened Nicias sent word to Athens that they had two options: call off the expedition and evacuate Sicily, or send him reinforcements equal to the original force. Nicias believed it was impossible to capture Syracuse at this point, but once again he misplayed his hand; the Athenians chose to double down rather than abandon the Sicilian Expedition. While Athens prepared to send reinforcements, Sparta had had enough. In 414 BC they formally abandoned the Peace of Nicias and openly declared war against Athens.

Throughout 414 and 413 BC, the Syracusans and their growing number of allies continued to hack away at the Athenians surrounding the city. Gylippus was a talented and flexible leader, capturing the Athenian naval base in early 413 BC and restricting their naval movement.

Let’s take a moment and see what we’re looking at here. Despite one of three generals being out of action – one dead, and the other a traitor – Athens could not stand to abandon the Sicilian Expedition. They could have pulled all their troops and ships out while they still had the chance, especially since it was obvious that the campaign would never deliver what Alcibiades had promised in those dreamy days before the war had resumed. Instead, though, the people of Athens – the most educated, philosophical, thoughtful people in the world at the time – chose again and again to double down on a losing game rather than examine the logic that brought them there in the first place. By failing to acknowledge their initial mistakes, they fell into the “sunk cost fallacy”. Instead of cutting their losses, they threw more chips into a losing hand. This more than anything was what transformed the Sicilian Expedition from defeat into disaster.

The second Athenian force set sail in the spring of 413 BC, this time under the command of the great Demosthenes – the man who had so humiliated the Spartans at Pylos & Sphacteria. Gylippus launched constant attacks to keep Nicias’ surviving soldiers on their toes, but was unable to eliminate them before Demosthenes arrived. The brilliant Athenian general took command from the cautious, unwell Nicias, and it seemed in July 413 BC like the Athenians might still have a chance to win this thing. He immediately launched a daring night attack to regain the encircling lines around the city. At first he succeeded, but in the darkened struggle the Athenian columns lost their way. Clashing with the motivated Syracusans under Gylippus, the Athenian hoplites suffered heavily in the darkness and had to retreat. The situation at Syracuse was beyond even the intervention of the brilliant, flexible Demosthenes.

With no other options available, Demosthenes decided that it was time to abandon the expedition. Nicias was finally persuaded to agree, especially when Spartan reinforcements began to flood into Syracuse. However, a lunar eclipse on August 27, 413 BC convinced the superstitious Nicias that the Athenian forces should wait a month before setting sail. Gylippus, realizing that this was his chance to not just defeat but destroy his foes, pounced. The Syracusan and Spartan fleets parked their ships across the mouth of the harbor where the Athenians were anchored, and chained their triremes together. The small space of the harbor prevented the Athenian ships from maneuvering, and the subsequent battles only confirmed that the Athenian fleet was trapped. After a series of futile attacks, Demosthenes decided that they had to fight their way out by land and hope to reach the sea by some other route. The Athenians fled, and the Syracusans led by their Spartan general followed.

It was a hopeless venture. The Athenians had to leave all their wounded and sick behind; numbering 40,000 men, they tried to fight their way south to a landing site where the handful of remaining triremes could pick them up. They were harassed the entire way by the Sicilians, whose superior cavalry took a toll on the starving and sick Athenian force. The retreat turned into a struggle for survival, as stragglers and lost units were snapped up by their pursuing foes. At some point, Demosthenes and 6,000 Athenians were isolated from Nicias’ main column, and forced to surrender; the remnants of the Athenian column reached the Assinarus River, where Syracusan forces waited on the other side. In scenes of utter depravity, dehydrated Athenians literally fought each other for a gulp of water from the trickling river as the Sicilians descended on them from both sides. By far the worst slaughter of the campaign took place on the banks of the Assinarus, which resulted in the capture or death of the remainder of the Expedition.

It was a massive disaster. Of the 50,000 or so Athenians or allies that had been committed to Sicily, barely a man escaped; only 7,000 survived, and most of these were sold into slavery across the wider Mediterranean world. No high-ranking Athenian leader survived the debacle. Demosthenes was executed outright, the Spartans having never forgiven him for their humiliating defeat at Sphacteria. Nicias, against Gylippus’ impassioned pleas, was executed as well to prevent his possible escape. Every other Athenian died laboring in the mines of Syracuse. Rarely has a military expedition of such magnitude and such importance to its country been destroyed so utterly and so callously.

The Sicilian Expedition was a shattering Athenian defeat from which they would never recover. So much manpower, so many resources, and – less measurable but no less important – so much hope had been poured into Sicily that the ultimate disaster was nearly crippling. The deaths of Demosthenes and Nicias, as well as the defection of Alcibiades, rendered Athens without strong leadership when they needed it most. The truce was over, the great Greek war was back on, and Athens had just spent exorbitant amounts of blood and treasure for no gain whatsoever.

Not only had the Expedition cost Athens much, it had placed the city in a vulnerable position, and now outright destruction was possible for the first time in the Peloponnesian War. No single act of hubris in human history had worse consequences than the Sicilian Expedition. It wasn’t just a failure; it placed the entire future of its nation in jeopardy.

The bad decisions are numerous. The decision of striking Sicily at all is highly questionable on its own, since the logic didn’t make any sense. The rationale behind committing so MANY troops to the campaign was flimsy at best. The wisdom of trying to put the leading general on trial due to political disagreements turned out to be foolish, since it sent him into the arms of the enemy. The numerous tactical mistakes and decision points at Syracuse itself only exacerbated previous mistakes. Above all, though, the decision to double down by sending so many reinforcements and ships when the Expedition was clearly a bust made a ruinous situation even worse. Athens threw good money after bad, and it made the inevitable disaster so much worse.

The Peloponnesian War was ON yet again, and Athens was clearly on the backfoot. Who would come to their rescue? Would you believe that it was the treasonous, backstabbing, opportunistic, crazy figure of Alcibiades? If you don’t believe it, prepare to. When Part V rolls around next month, all I’m gonna DO is talk about Alcibiades and his crazy-ass career.

102 views0 comments

Recent Posts

See All


bottom of page