6 March] 1856 in Moscow – 16 August 1919 in 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.

[1] As Foreign Minister, he assented to Austria-Hungary's annexation of Bosnia and Herzegovina in 1908 in exchange for Austrian support for the opening of the Turkish Straits to Russian warships.

In one of the secret articles of the renewed League of the Three Emperors of 1881, Austria-Hungary had asserted the right 'to annex Bosnia and Herzegovina at whatever moment she shall deem opportune', and the claim was repeated intermittently in Austro-Russian agreements.

Aehrenthal's announcement of the annexation on 5 October 1908, secured through alterations of the terms of the Treaty of Berlin at the expense of the Ottoman Empire, occasioned a major European crisis.

[7] The impasse in diplomacy was resolved only by the St Petersburg note of March 1909 in which the Germans demanded that the Russians at last recognize the annexation and urge Serbia to do likewise.

The historian Christopher Clark however, in his 2012 study of the causes of the First World War The Sleepwalkers, has challenged this view: "the evidence suggests that the crisis took the course it did because Izvolsky lied in the most extravagant fashion in order to save his job and reputation.

"[9] The years following the annexation crisis, with an atmosphere of increased 'chauvinist popular emotion' and with a sense of humiliation in a sphere of vital interest, saw the Russians launch a substantial programme of military investment.

[10] Upon becoming ambassador in Paris in 1910, Izvolsky devoted his energies to strengthening Russia's anti-German alliance with both the French Third Republic and the United Kingdom and encouraging Russian rearmament.

"[11] His daughter, though shocked, later attributed her father's words to, "the long-repressed bitterness he had felt, at seeing the abject subservience of the Orthodox Hierarchy to the Tsar, and the corrupting influence of Rasputin.

[12] His brother — Piotr Petrovich Izvolski (1863—1928) — was Oberprocurator of the Most Holy Synod until he resigned, allegedly in protest over the growing influence of Grigory Rasputin over appointments to the Church Hierarchy.

Alexander Izvolsky married Countess Marguerite von Toll, a Baltic German noblewoman of great charm whose influence at court was impeded by her ignorance of the Russian language.