4. The first phase of the War is named after Spartan king Archidamus II
The first phase of Peloponnesian War, which is known as the Archidamian War after Sparta’s king Archidamus II, lasted from 431 BC to 421 BC. City-states in the Peloponnesian League, except Corinth, were land-based powers with large nearly unbeatable armies while the Athenian Empire relied on its fleet which was the most powerful in Greece. They maintained their supremacy in their domains and were unable to win any decisive battles.
5. Archidamian War was brought to an end the treaty known as Peace of Nicias
Athens was able to capture 300 to 400 Spartan soldiers after winning the Battle of Sphacteria while Sparta captured the Athenian colony Amphipolis on which Athens relied heavily for funds. Athenian attempt to regain Amphipolis was unsuccessful as Sparta defeated them at the Battle of Amphipolis in 422 BC. The Spartans and Athenians agreed to exchange the hostages for the territory and signed the Peace of Nicias which lasted for 6 years.