The concept of genocide can be applied to historical events of the past . The preamble to the CPPCG states that " at all periods of history genocide has inflicted great losses on humanity . " Revisionist attempts to challenge or affirm claims of genocide are illegal in some countries . For example , several European countries ban the denial of the Holocaust or the Armenian Genocide , while in Turkey referring to the mass killings of Armenians , Greeks , Assyrians and Maronites as genocides may be prosecuted under Article 301
mass killings of Armenians
Armenian Genocide
Genocide