Quadruple Alliance
In European history, three military alliances of four nations:
The Quadruple Alliance 1718
Austria, Britain, France, and the United Provinces (Netherlands) joined forces to prevent Spain from annexing Sardinia and Sicily;
The Quadruple Alliance 1813
Austria, Britain, Prussia, and Russia allied to defeat the French emperor Napoleon; renewed in 1815 and 1818. See Congress of
Vienna.
The Quadruple Alliance 1834
Britain, France, Portugal, and Spain guaranteed the constitutional monarchies of Spain and Portugal against rebels in the Carlist War.
