The Triple Entente (from French entente [tt] meaning "friendship, understanding, agreement") describes the informal understanding between the Russian Empire, the French Third Republic and the United Kingdom of Great Britain and Ireland. It was built upon the Franco-Russian Alliance of 1894, the Entente Cordiale of 1904 between Paris and London, and the Anglo-Russian Entente of 1907. It formed a powerful counterweight to the Triple Alliance of Germany, Austria-Hungary, and Italy. The Triple Entente, unlike the Triple Alliance or the Franco-Russian Alliance itself, was not an alliance of mutual defence.

The Franco-Japanese Treaty of 1907 was a key part of building a coalition as France took the lead in creating alliances with Japan, Russia, and (informally) with Britain. Japan wanted to raise a loan in Paris, so France made the loan contingent on a Russo-Japanese agreement and a Japanese guarantee for France's strategically vulnerable possessions in Indochina. Britain encouraged the Russo-Japanese rapprochement. Thus was built the Triple Entente coalition that fought World War I.At the start of World War I in 1914, all three Triple Entente members entered it as Allied Powers against the Central Powers: Germany and Austria-Hungary. On September 4, 1914, the Triple Entente issued a declaration undertaking not to conclude a separate peace and only to demand terms of peace agreed between the three parties. Historians continue to debate the importance of the alliance system as one of the causes of World War I.

Count Alexander Petrovich Izvolsky or Iswolsky (Russian: Алекса́ндр Петро́вич Изво́льский, 18 March [O.S. 6 March] 1856, Moscow – 16 August 1919, Paris) was a Russian diplomat remembered as a major architect of Russia's alliance with Great Britain during the years leading to the outbreak of the First World War in 1914. As Foreign Minister, he assented to the Austro-Hungarian annexation of Bosnia and Herzegovina in 1908 in exchange for Austrian support for the opening of the Turkish Straits to Russian warships. In the resultant Bosnian Crisis of 1908–1909 the Powers did not accept the opening of the Straits. Izvolsky, publicly humiliated and destroyed by the debacle, resigned as Foreign Minister

in 1910.