Sparta Summons Allied Aid; Athenian Force Led by Cimon

A year into the Ithome siege, Sparta’s leaders assessed a familiar mountain and an unfamiliar risk. The rebel fortress held; sorties stung; rations stretched. So they did what confederacies do: they called for help. Thucydides, in the Pentecontaetia, notes the request that went out across the Peloponnese and beyond [9]. It reached Athens, where Cimon, victor at the Eurymedon and friend to Sparta, argued that Greek solidarity required aid.

Athens sent a force—Thucydides speaks of an Athenian contingent; later traditions give numbers such as 4,000 hoplites—with Cimon at its head [9][20]. They crossed the Isthmus of Corinth, passed through Megara, and moved down the western Peloponnese toward the siege lines under Ithome. The blue of the Corinthian Gulf on their left, the green of Arcadian hills to their right—the march embodied an alliance in motion.

At Sparta’s camp near Stenyclerus, greetings were exchanged with ritual care. The Athenians’ owl-emblazoned shields caught the same sun that browned Spartan cloaks. The sound of many dialects rose above the creak of wagons: Corinthians, Tegeans, Aeginetans, and now Athenians. The tactic seemed straightforward—add weight to the siege, try new assaults, tighten the noose. But the politics trembling underneath were anything but simple [9][20].

Athens and Sparta had cooperated before. Yet they represented different social orders. A citizenry mobilized by naval pay and assembly votes met a citizenry fed by bound labor and governed by gerousia and ephors. At Ithome’s foot, the difference sharpened. Athenians were reputed innovators—engineers of rams and ladders—and Spartans prized steadiness over novelty. Within that pairing simmered a fear Thucydides names with a single Greek verb: neōterizein, “to innovate” [9].

As the Athenians took their place in the line, Sparta measured the gain against an unspoken risk. What if Athenian commanders, working closely with helot defectors and rebels, saw opportunity for new alignments? What if their presence became a magnet for unrest across the Pamisos? The alliance was a gamble: more men, more minds—and one mind too many, perhaps, for Sparta’s comfort.

The diplomatic ledger shifted in days, not weeks. The Athenians had barely lowered their packs before Spartan anxiety peaked. The next chapter would be a dismissal—one that sounded, in the quiet under Ithome’s walls, louder than any ram.