The expedition was hampered from the outset by uncertainty in its purpose and command structure—political manoeuvring in Athens swelled a lightweight force of twenty ships into a massive armada, and the expedition's primary proponent, Alcibiades, was recalled from command to stand trial before the fleet even reached Sicily. Still, the Athenians achieved early successes. Syracuse, the most powerful state in Sicily, responded exceptionally slowly to the Athenian threat and, as a result, was almost completely invested before the arrival of back up in the form of Spartan general, Gylippus, who galvanized its inhabitants into action. From that point forward, however, as the Athenians ceded the initiative to their newly energized opponents, the tide of the conflict shifted. A massive reinforcing armada from Athens briefly gave the Athenians the upper hand once more, but a disastrous failed assault on a strategic high point and several crippling naval defeats damaged the Athenian soldiers' ability to continue fighting and also their morale. The Athenians attempted a last-ditch evacuation from Syracuse. The evacuation failed, and nearly the entire expedition were captured or were destroyed in Sicily.