The general Christian revolution thus seemed fairly launched, and in the first panic the threatened Moslems began reprisals of an equally general kind. In the larger Turkish cities there were massacres of Christian minorities, and the Government lent countenance to them by murdering its own principal Christian official Gregorios, the Greek patriarch at Constantinople, on April 22, 1821. But Sultan Mahmud quickly recovered himself. He saw that his empire could not survive a racial war, and determined to prevent the present revolt from assuming such a character. His plan was to localize it by stamping out the more distant sparks with all his energy, before concentrating his force at leisure upon the main conflagration. This policy was justified by the event. On March 6 the ‘Philikì Hetairia’ at Odessa had opened its own operations in grandiose style by sending a filibustering expedition across the Russo-Turkish frontier under command of Prince Alexander Hypsilantis, a Phanariot in the Russian service. Hypsilantis played for a general revolt of the Ruman population in the Danubian Principalities and a declaration of war against Turkey on the part of Russia. But the Rumans had no desire to assist the Greek bureaucrats who oppressed them, and the Tsar Alexander had been converted by the experiences of 1812-13 to a pacifistic respect for the _status quo_. Prince Hypsilantis was driven ignominiously to internment across the Austrian frontier, little more than a hundred days after his expedition began; and his fiasco assured the Ottoman Government of two encouraging facts—that the revolution would not carry away the whole Orthodox population but would at any rate confine itself to the Greeks; and that the struggle against it would be fought out for the present, at least, without foreign intervention. In the other direction, however, rebellion was spreading northward from Peloponnesos to continental Greece. Galaxídhi revolted in April, and was followed in June by Mesolonghi—a prosperous town of fishermen, impregnably situated in the midst of the lagoons at the mouth of the Aspropotamo, beyond the narrows of the Korinthian Gulf. By the end of the month, north-western Greece was free as far as the outposts of Khurshid Pasha beyond the Gulf of Arta.