The Porajmos, also known as the Romani Genocide or the Gypsy Holocaust, was the effort by Nazi Germany and its World War II allies to commit genocide against Europe's Romani people.
Under Adolf Hitler, a supplementary decree to the Nuremberg Laws was issued on 26 November 1935, classifying Gypsies as "enemies of the race-based state", thereby placing them in the same category as the Jews. Thus, in some ways the fate of the Roma in Europe paralleled that of the Jews in the Holocaust.
Historians estimate that between 220,000 and 500,000 Romani were killed by the Germans and their collaborators—25% to over 50% of the slightly fewer than 1 million Roma in Europe at the time. A more thorough research by Ian Hancock revealed the death toll to be at about 1.5 million.
In 1982, West Germany formally recognized that Germany had committed genocide against the Romani. In 2011, Poland officially adopted 2 August as a day of commemoration of the Romani genocide.