Purposeful killing of a racial, political, religious, or cultural group = Genocide.
A table listing historical genocides, including the Ottoman Empire's killing of Armenians in 1915, Nazi Germany's Holocaust in Europe (1939-1945), Stalin's purges in the USSR (1930s), Pol Pot's regime in Cambodia (1976), the Tutsi genocide in Rwanda (1990s), and the Bosnian Serbs' actions in former Yugoslavia (1990s).