The two countries involved in the Peloponnesian War were Athens and Sparta. This conflict, lasting from 431 to 404 BCE, was primarily a struggle for power and dominance in ancient Greece. Athens, with its powerful navy and empire, clashed with the militaristic and land-based Sparta. The war fundamentally reshaped the political landscape of Greece, leading to the eventual defeat of Athens and the rise of Sparta as a dominant power, although this dominance was short-lived. The war's complex causes included economic interests, alliances, and mutual suspicion, representing a significant chapter in classical antiquity.