WORLD HISTORY

Detailed explanation-1: -In 431, Sparta and its Peloponnesian League allies declared war on Athens and began the Peloponnesian War, beginning the next phase in the endless competition between the two superpowers.

Detailed explanation-2: -The spectacular defeat of the Persians at Salamis in 480 led to the formation of a more permanent alliance. Three years later negotiations, led by Aristides of Athens, began on the Greek island of Delos. The result was the Delian League, a sort of ancient equivalent to NATO.

Detailed explanation-3: -The Delian League, also known as the Athenian League, was an alliance of Greek city-states led by Athens during the 5th century BCE in the Classical Greek period.

Detailed explanation-4: -The Wars of the Delian League (477–449 BC) were a series of campaigns fought between the Delian League of Athens and her allies (and later subjects), and the Achaemenid Empire of Persia.

Detailed explanation-5: -The Delian league was a new alliance against the Persians, but under Athenian leadership. Clear lines of power and sides again. In winter of 478, the Delian League was officially formed on the island of Delos.