Since the Red Army invasion of 1921, Georgia had been one of the 12 member-republics of the USSR, a communist and authoritarian federation. Despite the "de jure" status as a sovereign nation of the Socialist Soviet Republic of Georgia, nationalistic feelings developed largely in the 1970s, feelings that were be repeated across the Soviet world. Major economic problems, the dictatorial nature of government, and repression of nationalistic symbols lead to several protests in Georgia, culminating with the 9 April 1989 Tragedy, when a protest in Tbilisi is repressed by the authorities and results in the death of 21 people and the arrest of the main opposition leaders, including Zviad Gamsakhurdia.