Roma were also discriminated against before the Nazi era. And the situation became worse after Hitler came to power in January 1933. In the mid-1930s, the Nazis banned Roma from working in certain jobs; they were forcibly sterilized in the form of ethnic cleansing and mass internal Nazi camps.
It is estimated that around 500,000 Roma were killed during World War II, but the exact number will never be known because most homicides are nowhere to be found and researchers believe their numbers are much higher.
With little or no record, many families will never know what actually happened to them.
Otherwise Dr. Robert Ritter in charge of the racial hygiene research center at the Reich Health Institute in 1938 started the project with a thorough analysis of the "racial characteristics" of the Roma. Scientists checked their health, took blood and measured their heads.
"They invented various racist ideas about Roma for genetic reasons of inferiority," said Barbara Vrnock, head of the Holocaust Center.