By the Treaty of London of July 6, 1827, and following the intense emotion aroused internationally by the Greek Revolution and mainly by the Exodus from Missolonghi, England, France and Russia decided to intervene in every possible manner in order to achieve the cease of the battles between the Greeks rebelling and the Ottoman troops. In application of this agreement the admirals of the three Powers, who were in charge of the naval forces in the Eastern Mediterranean received orders to prevent the reinforcements sent to Ibrahim in ships and soldiers from Egypt and the transfer of female Greek war prisoners and their children to the slave markets of Africa.

On October 8/20 the three Allied fleets defeated the Turkish-Egyptian one, which supported Ibrahim from the sea. The naval battle took place in the gulf of Navarino, Messenia, in front of which there is the island of Sphakteria as a natural barrier. The British Codrington, the French De Rigny and the Russian van Heiden (of Dutch origin) were at the head of the allied fleet. The blow against the Sultan and Ibrahim was severe, but the Egyptian troops remained in the Peloponnese for one more year. The Three Powers sent a detachment of French cavalry under General Maison to chase Ibrahim away from Morea.

Photograph: George Philip Reinagle, The battle of Navarino, 20 October 1827, National Maritime Museum, Greenwich, London