Austria, Britain and France form a secret defensive alliance against Prussia and Russia

Background. The Congress of Vienna (1814–1815) aimed to reorganize Europe after Napoleon's fall. Talleyrand negotiated for France, while Castlereagh represented Britain. Metternich chaired the Congress. The secret treaty emerged from tensions regarding Prussian and Russian ambitions, leading to a defensive pact among the three powers to prevent their plans from coming to fruition.

Signatories. Talleyrand, a key agent of the Bourbon Restoration, was named as France's signatory to the secret treaty. Castlereagh, who had negotiated the quadruple alliance between Britain, Austria, Russia, and Prussia at Chaumont in March 1814, was named for Britain. Metternich, the Austrian statesman who chaired the Congress, was named for Austria. The treaty text names these three men as its signatories.

Congress Context. The treaty was signed among only the three nations, agreeing to war against Russia and Prussia if necessary. This occurred while Talleyrand remained in Vienna during the Hundred Days. Castlereagh returned to England in February 1815, after which Wellington represented Britain.