The city of Sparta lies at the southern end of the central Laconian plain, on the right bank of the river Eurotas.
Sparta had the best army in ancient Greece; it was the most powerful state before the rise of Athens, and many would argue that it remained so afterwards. Also, following the defeat of Athens in the First Peloponnesian War, it became a great naval power. Sparta and Athens were reluctant allies against the Persians, but became rivals thereafter. The greatest series of conflicts between the two states, which resulted in the dismantling of the Athenian Empire, is called the Peloponnesian War. Athenian attempts to control Greece and take over the Spartan role of 'guardian of Hellenism' ended in failure. The first ever defeat of a Spartan hoplite army at full strength occurred at the Battle of Leuctra in 371 BC, after which Sparta's position as the dominant Greek city-state swiftly disappeared with the loss of its Helots. By the time of the rise of Alexander the Great in 336 BC, Sparta was a shadow of its former self, clinging to an isolated independence. During the Punic Wars Sparta was an ally of the Roman Republic. Spartan political independence was put to an end when it was eventually overpowered by its ancient rival Argos and forced into the Achaean League - which became Greece.