With the Treaty of London (July 1827), Great Britain, Russia and France
invited the two opposite sides to cease hostilities and proceed with negotiations. In reality, the three Great Powers had agreed, each one for its own reasons, to do whatever necessary, even if this meant war, in order to oblige the Ottoman Empire to accept the creation of an autonomous Greek state. Great Britain was in favour of a Greek state with which it would maintain friendly relations and which would be economically dependent on Great Britain as an answer to Russian intention in the Balkans and the Eastern Mediterranean. Moreover, France
followed the antagonism of the other two countries, which was positive for the Greek cause, probably in order not to be left behind in developments in this very important region as far as economic and geopolitical interests are concerned.
Thus, the navies of Great Britain and France, which were already
in the Ionian Sea, were obliged to prevent all naval actions,
even the transport of armed men, munitions and provisions.
The terms of the Treaty of London, excluding the secret article, were
communicated to the Greek side in the middle of August 1827 and toward the end of the same month they were accepted. Nevertheless, part of the Greek
navy continued its operations in the Gulf of Corinth.
Toward the middle of September the treaty was communicated to Ibrahim as well, which maintained a reserved position waiting for directions from the
Sublime Porte. However, neither did Ibrahim seem to comply with the invitation for immediate truce; instead he attempted to transfer armed men from Navarino, where his fleet was anchored, to Patras at the end of September.
His actions were not met with equal tolerance. On 8 October the British, French and Russian navies entered the Gulf of Navarino and
clashed with the Egyptian fleet. Within four hours of strong cannonade the ships of the Allies, which were fewer (about 30 against 90) but better equipped, destroyed almost completely the fleet of the enemy.
This development triggered preparations for war in the Ottoman Empire and Russia, towards which the fury of the Ottomans was directed. Despite the efforts mainly of Great Britain to defuse the tension between the two countries, the new Russo-Ottoman War was announced in April 1828. In June of the same year the three Powers agreed on sending French troops to the
Peloponnese to supervise the completion of the withdrawal of Ibrahim. After thirteen months, in mid-September 1829, the Ottoman Empire had to capitulate, accepting the decisions of the triple alliance with regard to the Greek cause.
Seven years after its outbreak, the Greek Revolution
was unexpectedly justified (after the suspension of hostilities about 1825-1827) in the field of international diplomacy.
What remained to be determined was the degree of independence and the frontiers of the Greek state.