Part 3 introduces Alcibiades, an Athenian statesman who defects to Sparta and becomes an adviser and strategist. In particular, he suggests that Sparta takes the war to Syracuse, in Sicily, during which Athens suffers a major blow (including the capture of their entire expeditionary force). The Spartan Lysander, chief of its naval forces, begins to rise in power, and he eventually defeats the Athenian navy (which enables him to blockade Athens) and finally ends the war by successfully invading and subjugating Athens. Agesilaus, who becomes one of the kings of Sparta, finally sees Sparta become the dominant power in Greece. But decadence and corruption follow, along with a drastic reduction in the number of Spartan citizens. In time, these events lead to an irreversible decline in Sparta's fortunes, leading to war with Thebes and, in 371 BC, the end of Spartan pre-eminence after the battle of Leuctra.
The Spartans was a 3-part historical documentary series first broadcast on UK terrestrial Channel 4 in 2003, presented by Bettany Hughes. A book, The Spartans: An epic history by Paul Cartledge accompanied the series.