Book VII

Spartan general Gylippus, considered too late to save Syracuse, arrives through Himera with an overland force. He rallies the Syracusans, marches to their walls before the Athenians can complete the investment, and immediately begins offensive operations.

Gylippus begins building a cross-wall to cut off the Athenian siege lines on Epipolae. After initial Athenian successes, the Syracusans complete the cross-wall and the Athenians lose their chance of completing the investment of Syracuse.

The Athenian generals, after failures on land and sea, debate withdrawal. Demosthenes arrives with a large relief force and attempts a night assault on the Syracusan lines at Epipolae; the attack ends in rout and confusion.

The Athenians attempt retreat by land after their fleet is destroyed. Both Nicias and Demosthenes surrender; both are executed. The survivors are enslaved and worked to death in the Syracusan stone quarries. It is the greatest disaster in Athenian history.