Quadruple Alliance

Quadruple Alliance may refer to:

• The October 1673 alliance between the Dutch Republic, Emperor Leopold, Spain, and Charles IV, Duke of Lorraine, during the Franco-Dutch War.
• The 1718 alliance between Austria, France, the Netherlands, and Great Britain during the War of the Quadruple Alliance.
• The Treaty of Warsaw (1745) between Great Britain, Austria, the Netherlands, and Saxony (the Quadruple Alliance) to uphold the Pragmatic Sanction, allowing Maria Theresa to succeed to the Habsburg dominions.
• The Quadruple Alliance (1815) between the United Kingdom, Austria, Prussia, and Russia following the Napoleonic Wars.
• The 1834 Quadruple Alliance between the United Kingdom, France, Spain, and Portugal to enforce the Concession of Evoramonte.
• The Quadruple Alliance (1912-1913), also known as the Balkan League, representing a system of alliances between Bulgaria, Greece, Montenegro and Serbia
• The Quadruple Alliance (1915-1918), formed when Bulgaria joined the other three Central Powers of World War I (Germany, Austria-Hungary, and the Ottoman Empire).
• The major Allies of World War II: the United States, Great Britain, China, and the USSR, dubbed the "Big Four" or the "Four Policemen".
• In Harry Turtledove's Southern Victory Series, set in an alternate reality where the Confederate States win the American Civil War, a Quadruple Alliance (the United States, Germany, Austria-Hungary and the Ottoman Empire), fights in an alternate Great War (1914-1917) against the Quadruple Entente (the Confederate States, Great Britain, France and Russia).