The Peloponnesian Wars were a series of conflicts fought between the city-states of Athens and Sparta, along with their respective allies, from 431 to 404 BCE. This prolonged struggle was primarily driven by power dynamics and territorial disputes, leading to significant shifts in ancient Greek politics and society. The wars are typically divided into three phases: the Archidamian War, the Sicilian Expedition, and the Ionian or Decelean War. Ultimately, Sparta emerged victorious, resulting in the decline of Athenian power and the establishment of a brief Spartan hegemony over Greece.