List of military alliances


A military alliance is a legally binding treaty between two or more parties in which the contracting parties agree to mutually protect one another militarily in case of an armed conflict. Military alliances differ from coalitions, which are formed in response to a specific crisis and last until the crisis is resolved. Military alliances can be bilateral or multilateral. Numerous forms of military and defensive alliances have existed between states since early human history. This is a comprehensive list of former and present military alliances.

Bilateral military alliances

YearsNameMembers
493 BCFoedus CassianumRoman Republic
Latin League
215 BCMacedonian–Carthaginian TreatyMacedonia
Carthage
433–554Banner of Silla.svg.png" />Military Banner of Silla.svg

Multilateral military alliances

YearsNameMembers
c. 7th century–338 BCLatin LeagueAbout 30 villages and tribes in the region of Latium
c. 6th century–366 BCPeloponnesian LeagueVarious city-states in the Peloponnese, dominated by Sparta
478–404 BCDelian LeagueSee Members of the Delian League
1167–1250Lombard LeagueNumerous cities in medieval Lombardy, modern Northern Italy
1266–1320Byzantine–Mongol AllianceByzantine Empire