History 25 Massacres 12 Nanking Massacre, Nanjing, Jiangsu Sheng, China, 1937 10 Atrocities 8 Genocide 6 Armenian massacres, 1915-1923 5 Sino-Japanese War, 1937-1945 5 World War, 1939-1945 4 Demonstrations 3 Historiography 3 Holocaust, Jewish (1939-1945) 3 Political violence 3 Politics and government 3 Armenians 2 Bloody Sunday, Derry, Northern Ireland, 1972 2 Ethnic relations 2 Foreign relations 2 Katyn Massacre, Katyn, Russia, 1940 2 My Lai Massacre, Vietnam, 1968 2 Political atrocities 2 Psychological aspects 2 Vietnamese Conflict, 1961-1975 2 War crimes 2 Armenian massacres 1 Armenian massacres survivors 1 Armenian question 1 Collective memory 1 Columbine High School Massacre, Littleton, Colo., 1999 1 Communication 1 Crimes against humanity 1