The Powers agreed, by the Treaty of London (1827), to force the Ottoman government to grant the Greeks autonomy within the empire and despatched naval squadrons to Greece to enforce their policy. The decisive Allied naval victory at the Battle of Navarino broke the military power of the Ottomans and their Egyptian allies. Victory saved the fledgling Greek Republic from collapse. But it required two more military interventions, by Russia in the form of the Russo-Turkish War of 1828–29 and by a French expeditionary force to the Peloponnese to force the withdrawal of Ottoman forces from central and southern Greece and to finally secure Greek independence. Greek nationalists proclaimed a new "Great Idea" whereby the little nation of 800,000 would expand to include all the millions of Greek Orthodox believers in the region now under Ottoman control, with Constantinople to be reclaimed as its capital. This idea was the antithesis of the British goal of maintaining the Ottoman Empire, and London systematically opposed the Greeks until the Great Idea finally collapsed in 1922 when Turkey drove the Greeks out of Anatolia.