An agreement between states to fight together against a common enemy. Such alliances might be made either for a limited period or for all time. In a full offensive and defensive alliance it was commonly stated that the participating states were to ‘have the same friends and enemies’: that formulation might be used when the alliance was on an equal basis, but it could be adapted to circumstances in which one participant was inferior to the other, as in 404 bc when Athens undertook both to have the same friends and enemies as Sparta and to follow Sparta's lead.
The Peloponnesian League, built up by Sparta in the second half of the 6th cent. bc, was the first instance of a league of allies united for purposes of foreign policy. Such leagues tended to be formed with a dominant state as leader, influential through possession of executive power even if not formally privileged in decision‐making, and with a council which played a part in decision‐making and enabled representatives of the member states to express opinions and vote. Other examples were the Delian League, the Second Athenian Confederacy, and the Corinthian League organized by Philip II of Macedon. In the Delian League Athens came to interfere in various ways with the autonomy of the members; and to win support for her Second Confederacy, she gave undertakings that such interference would not be repeated.
Subjects: Classical Studies.