--- Independence Day
Alexander Ypsilantis was elected as the head of the Filiki Eteria in April 1820 and took upon him the task of planning the insurrection. Ypsilantis' intention was to raise all the Christians of the Balkans in rebellion and perhaps force Russia to intervene on their behalf. On 22 February, he crossed the river Prut with his followers, entering the Danubian Principalities. In order to encourage the local Romanian Christians to join him, he announced that he had "the support of a Great Power", implying Russia. Two days after crossing the Prut, Ypsilantis issued a proclamation calling all Greeks and Christians to rise up against the Ottomans. Michael Soutzos, then Prince of Moldavy and a member of Filiki Etaireia, set his guard at Ypsilantis' disposal. In the meanwhile, Patriarch Gregory V of Constantinople and the Synod had anathematized and excommunicated both Ypsilantis and Soutzos issuing many encyclicals, an explicit denounce of the Revolution in line with the Orthodox Church policy. "Fight for Faith and Motherland! The time has come, O Hellenes. Long ago the people of Europe, fighting for their own rights and liberties, invited us to imitation ... The enlightened peoples of Europe are occupied in restoring the same well-being, and, full of gratitude for the benefactions of our forefathers towards them, desire the liberation of Greece. We, seemingly worthy of ancestral virtue and of the present century, are hopeful that we will achieve their defense and help. Many of these freedom-lovers want to come and fight alongside us ... Who then hinders your manly arms? Our cowardly enemy is sick and weak. Our generals are experienced, and all our fellow countrymen are full of enthusiasm. Unite, then, O brave and magnanimous Greeks! Let national phalanxes be formed, let patriotic legions appear and you will see those old giants of despotism fall themselves, before our triumphant banners." Ypsilantis' Proclamation at Iaşi. Instead of directly advancing on Brăila, where he arguably could have prevented Ottoman armies from entering the Principalities, and where he might have forced Russia to accept a fait accompli, Ypsilantis remained in Iaşi, and ordered the executions of several pro-Ottoman Moldavians. In Bucharest, where he had arrived in early April after some weeks delay, he decided that he could not rely on the Wallachian Pandurs to continue their Oltenian-based revolt and assist the Greek cause. The Pandur leader was Tudor Vladimirescu, who had already reached the outskirts of Bucharest on 16 March. In Bucharest, the relations of the two men deteriorated dramatically; Vladimirescu's first priority was to assert his authority against the newly appointed prince Scarlat Callimachi, trying to maintain relations with both Russia and the Ottomans.
The outbreak of the war was met by mass executions, pogrom-style attacks, the destruction of churches, and looting of Greek properties throughout the Empire. The most severe atrocities occurred in Constantinople, in what became known as the Constantinople Massacre of 1821. The Orthodox Patriarch Gregory V was executed on April 22, 1821 on the orders of the Sultan despite his opposition to the revolt, which caused outrage throughout Europe and resulted in increased support for the Greek rebels.
The Peloponnese, with its long tradition of resistance to the Ottomans, was to become the heartland of the revolt. In the early months of 1821, with the absence of the Ottoman governor of the Morea Mora valisi Hursid Pasha and many of his troops, the situation was favourable for the Greeks to rise against Ottoman occupation. The crucial meeting was held at Vostitsa (modern Aigion), where chieftains and prelates from all over the Peloponnese assembled on 26 January. There, Papaflessas, a pro-revolution priest who presented himself as representative of Filiki Eteria clashed with most of the civil leaders and members of the senior clergy, such as Metropolitan Germanos of Patras, who were sceptical and demanded guarantees about a Russian intervention. As news came of Ypsilantis' march into the Danubian Principalities, the atmosphere in the Peloponnese was tense, and by mid-March, sporadic incidents against Muslims occurred, heralding the start of the uprising. According to the tradition, the Revolution was declared on 25 March 1821 by Metropolitan Germanos who raised the banner with the cross in the Monastery of Agia Lavra, although some historians question the historicity of the event.