Greece suffered from foreign aggression and occupation, and spent more than four hundred years under the rule of the Ottoman Empire. The disaster was profound, the country was disintegrated, and the people's rebellion against oppression continued, and on March 25, 1821, the Greek people rebel against the rule of the Ottoman Empire. After eight years of struggle, the Greek people finally won in 1829 and became an autonomous state. In 1830, the independence was declared and the Greek kingdom was founded. In 1941, Greece was occupied by fascist Germany, and on October 15, 1944, the nation was liberated and regained independence. In June 1973, the sovereign monarchy was abolished and the Greek Republic was changed.