Sultan Mahmud II. believed that he could paralyse the movements of the Greeks by terrific cruelty.  On Easter Sunday, April 22, the Patriarch Gregorios and three other bishops were executed in Constantinople—­a deed which caused a thrill of horror from the Moslem capital to the mountains of Greece, and the palaces of St. Petersburg.  The sultan next strengthened his authority in Thrace and in Macedonia, and extinguished the flames of rebellion from Mount Athos to Olympus.

In Greece itself the patriots were triumphant.  Local senates were formed for the different districts, and a National Assembly met at Piada, three miles to the west of the site of the ancient Epidaurus, which formulated a constitution and proclaimed it on January 13, 1822.  This constitution established a central government consisting of a legislative assembly and an executive body of five members, with Prince Alexander Mavrocordato as President of Greece.

It is impossible here to go into the details of the war of independence which was carried on from 1822 to 1827.  The outstanding incidents were the triple siege and capitulation of the Acropolis at Athens; the campaigns of Ibrahim Pasha and his Egyptian army in the Morea; the defence of Mesolonghi by the Greeks with a courage and endurance, an energy and constancy which will awaken the sympathy of free men in every country as long as Grecian history endures; the two civil wars, for one of which the Primates were especially blamable; the dishonesty of the government, the rapacity of the military, the indiscipline of the navy; and the assistance given to the revolutionaries by Lord Byron and other English sympathisers.  Lord Byron arrived at Mesolonghi on January 5, 1824.  His short career in Greece was unconnected with any important military event, for he died on April 19; but the enthusiasm he awakened perhaps served Greece more than his personal exertions would have done had his life been prolonged, because it resulted in the provision of a fleet for the Greek nation by the English and American Philhellenes, commanded by Lord Cochrane.

By the beginning of 1827 the whole of Greece was laid waste, and the sufferings of the agricultural population were terrible.  At the same time, the greater part of the Greeks who bore arms against the Turks were fed by Greek committees in Switzerland, France, and Germany; while those in the United States directed their attention to the relief of the peaceful population.  It was felt that the intervention of the European powers could alone prevent the extermination of the population or their submission to the sultan.  On July 6, 1827, a treaty Between Great Britain, France, and Russia was signed at London to take common measures for the pacification of Greece, to enforce an armistice between the Greeks and the Turks, and, by an armed intervention, to secure to the Greeks virtual independence under the suzerainty of the sultan.  The Greeks accepted the armistice, but the Turks refused; and then followed the destruction of the Othoman fleet by the allied squadrons under Admiral Sir Edward Coddrington at Navarino, on October 21, 1827.